Lazy load chrome.* APIs

chrome/renderer/extensions/dispatcher.cc

Index: chrome/renderer/extensions/dispatcher.cc
diff --git a/chrome/renderer/extensions/dispatcher.cc b/chrome/renderer/extensions/dispatcher.cc
index 1c7ebc16c6039db74c0d9e71c68fd9cd2dd1ad11..c757e83fd4dd1dc3d8b4f8c9ea17d95df9fccab5 100644
--- a/chrome/renderer/extensions/dispatcher.cc
+++ b/chrome/renderer/extensions/dispatcher.cc
@@ -8,6 +8,7 @@
 #include "base/command_line.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/string_piece.h"
+#include "base/strings/string_split.h"
 #include "chrome/common/child_process_logging.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/chrome_version_info.h"
@@ -15,6 +16,7 @@
 #include "chrome/common/extensions/background_info.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/extensions/extension_messages.h"
+#include "chrome/common/extensions/features/feature.h"
 #include "chrome/common/extensions/manifest.h"
 #include "chrome/common/extensions/permissions/permission_set.h"
 #include "chrome/common/url_constants.h"
@@ -24,6 +26,7 @@
 #include "chrome/renderer/extensions/app_bindings.h"
 #include "chrome/renderer/extensions/app_runtime_custom_bindings.h"
 #include "chrome/renderer/extensions/app_window_custom_bindings.h"
+#include "chrome/renderer/extensions/binding_generating_native_handler.h"
 #include "chrome/renderer/extensions/chrome_v8_context.h"
 #include "chrome/renderer/extensions/chrome_v8_extension.h"
 #include "chrome/renderer/extensions/content_watcher.h"
@@ -40,7 +43,7 @@
 #include "chrome/renderer/extensions/media_galleries_custom_bindings.h"
 #include "chrome/renderer/extensions/miscellaneous_bindings.h"
 #include "chrome/renderer/extensions/module_system.h"
-#include "chrome/renderer/extensions/native_handler.h"
+#include "chrome/renderer/extensions/object_backed_native_handler.h"
 #include "chrome/renderer/extensions/page_actions_custom_bindings.h"
 #include "chrome/renderer/extensions/page_capture_custom_bindings.h"
 #include "chrome/renderer/extensions/request_sender.h"
@@ -92,24 +95,97 @@ static const char kEventDispatchFunction[] = "Event.dispatchEvent";
 static const char kOnSuspendEvent[] = "runtime.onSuspend";
 static const char kOnSuspendCanceledEvent[] = "runtime.onSuspendCanceled";
 
-class ChromeHiddenNativeHandler : public NativeHandler {
+static v8::Handle<v8::Object> GetOrCreateChrome(
+    v8::Handle<v8::Context> context) {
+  v8::Handle<v8::String> chrome_string(v8::String::New("chrome"));
+  v8::Handle<v8::Object> global(context->Global());
+  v8::Handle<v8::Value> chrome(global->Get(chrome_string));
+  if (chrome.IsEmpty() || chrome->IsUndefined()) {
+    v8::Handle<v8::Object> chrome_object(v8::Object::New());
+    global->Set(chrome_string, chrome_object);
+    return chrome_object;
+  }
+  CHECK(chrome->IsObject());
+  return chrome->ToObject();
+}
+
+class SchemaRegistryNativeHandler : public ObjectBackedNativeHandler {
  public:
-  explicit ChromeHiddenNativeHandler(v8::Isolate* isolate)
-      : NativeHandler(isolate) {
+  SchemaRegistryNativeHandler(V8SchemaRegistry* registry,
+                              v8::Handle<v8::Context> context)
+      : ObjectBackedNativeHandler(context),
+        registry_(registry) {
+    RouteFunction("GetSchema",
+        base::Bind(&SchemaRegistryNativeHandler::GetSchema,
+                   base::Unretained(this)));
+  }
+
+ private:
+  v8::Handle<v8::Value> GetSchema(const v8::Arguments& args) {
+    return registry_->GetSchema(*v8::String::AsciiValue(args[0]));
+  }
+
+  V8SchemaRegistry* registry_;
+};
+
+class V8ContextNativeHandler : public ObjectBackedNativeHandler {
+ public:
+  explicit V8ContextNativeHandler(ChromeV8Context* context)
+      : ObjectBackedNativeHandler(context->v8_context()),
+        context_(context) {
+    RouteFunction("GetAvailability",
+        base::Bind(&V8ContextNativeHandler::GetAvailability,
+                   base::Unretained(this)));
+  }
+
+ private:
+  v8::Handle<v8::Value> GetAvailability(const v8::Arguments& args) {
+    CHECK_EQ(args.Length(), 1);
+    std::string api_name = *v8::String::AsciiValue(args[0]->ToString());
+    Feature::Availability availability = context_->GetAvailability(api_name);
+
+    v8::Handle<v8::Object> ret = v8::Object::New();
+    ret->Set(v8::String::New("is_available"),
+             v8::Boolean::New(availability.is_available()));
+    ret->Set(v8::String::New("message"),
+             v8::String::New(availability.message().c_str()));
+    return ret;
+  }
+
+  ChromeV8Context* context_;
+};
+
+class ChromeHiddenNativeHandler : public ObjectBackedNativeHandler {
+ public:
+  explicit ChromeHiddenNativeHandler(v8::Handle<v8::Context> context)
+      : ObjectBackedNativeHandler(context) {
     RouteFunction("GetChromeHidden",
         base::Bind(&ChromeHiddenNativeHandler::GetChromeHidden,
                    base::Unretained(this)));
   }
 
   v8::Handle<v8::Value> GetChromeHidden(const v8::Arguments& args) {
-    return ChromeV8Context::GetOrCreateChromeHidden(v8::Context::GetCurrent());
+    return ChromeV8Context::GetOrCreateChromeHidden(v8_context());
   }
 };
 
-class PrintNativeHandler : public NativeHandler {
+class ChromeNativeHandler : public ObjectBackedNativeHandler {
  public:
-  explicit PrintNativeHandler(v8::Isolate* isolate)
-      : NativeHandler(isolate) {
+  explicit ChromeNativeHandler(v8::Handle<v8::Context> context)
+      : ObjectBackedNativeHandler(context) {
+    RouteFunction("GetChrome",
+        base::Bind(&ChromeNativeHandler::GetChrome, base::Unretained(this)));
+  }
+
+  v8::Handle<v8::Value> GetChrome(const v8::Arguments& args) {
+    return GetOrCreateChrome(v8_context());
+  }
+};
+
+class PrintNativeHandler : public ObjectBackedNativeHandler {
+ public:
+  explicit PrintNativeHandler(v8::Handle<v8::Context> context)
+      : ObjectBackedNativeHandler(context) {
     RouteFunction("Print",
         base::Bind(&PrintNativeHandler::Print,
                    base::Unretained(this)));
@@ -130,8 +206,9 @@ class PrintNativeHandler : public NativeHandler {
 
 class LazyBackgroundPageNativeHandler : public ChromeV8Extension {
  public:
-  explicit LazyBackgroundPageNativeHandler(Dispatcher* dispatcher)
-      : ChromeV8Extension(dispatcher) {
+  LazyBackgroundPageNativeHandler(Dispatcher* dispatcher,
+                                  v8::Handle<v8::Context> context)
+      : ChromeV8Extension(dispatcher, context) {
     RouteFunction("IncrementKeepaliveCount",
         base::Bind(&LazyBackgroundPageNativeHandler::IncrementKeepaliveCount,
                    base::Unretained(this)));
@@ -141,7 +218,8 @@ class LazyBackgroundPageNativeHandler : public ChromeV8Extension {
   }
 
   v8::Handle<v8::Value> IncrementKeepaliveCount(const v8::Arguments& args) {
-    ChromeV8Context* context = dispatcher()->v8_context_set().GetCurrent();
+    ChromeV8Context* context =
+        dispatcher()->v8_context_set().GetByV8Context(v8_context());
     if (!context)
       return v8::Undefined();
     RenderView* render_view = context->GetRenderView();
@@ -153,7 +231,8 @@ class LazyBackgroundPageNativeHandler : public ChromeV8Extension {
   }
 
   v8::Handle<v8::Value> DecrementKeepaliveCount(const v8::Arguments& args) {
-    ChromeV8Context* context = dispatcher()->v8_context_set().GetCurrent();
+    ChromeV8Context* context =
+        dispatcher()->v8_context_set().GetByV8Context(v8_context());
     if (!context)
       return v8::Undefined();
     RenderView* render_view = context->GetRenderView();
@@ -178,14 +257,14 @@ class LazyBackgroundPageNativeHandler : public ChromeV8Extension {
 
 class ProcessInfoNativeHandler : public ChromeV8Extension {
  public:
-  explicit ProcessInfoNativeHandler(
-      Dispatcher* dispatcher,
-      const std::string& extension_id,
-      const std::string& context_type,
-      bool is_incognito_context,
-      int manifest_version,
-      bool send_request_disabled)
-      : ChromeV8Extension(dispatcher),
+  ProcessInfoNativeHandler(Dispatcher* dispatcher,
+                           v8::Handle<v8::Context> context,
+                           const std::string& extension_id,
+                           const std::string& context_type,
+                           bool is_incognito_context,
+                           int manifest_version,
+                           bool send_request_disabled)
+      : ChromeV8Extension(dispatcher, context),
         extension_id_(extension_id),
         context_type_(context_type),
         is_incognito_context_(is_incognito_context),
@@ -241,13 +320,12 @@ class ProcessInfoNativeHandler : public ChromeV8Extension {
   bool send_request_disabled_;
 };
 
-class LoggingNativeHandler : public NativeHandler {
+class LoggingNativeHandler : public ObjectBackedNativeHandler {
  public:
-  explicit LoggingNativeHandler(v8::Isolate* isolate)
-      : NativeHandler(isolate) {
+  explicit LoggingNativeHandler(v8::Handle<v8::Context> context)
+      : ObjectBackedNativeHandler(context) {
     RouteFunction("DCHECK",
-        base::Bind(&LoggingNativeHandler::Dcheck,
-                   base::Unretained(this)));
+        base::Bind(&LoggingNativeHandler::Dcheck, base::Unretained(this)));
   }
 
   v8::Handle<v8::Value> Dcheck(const v8::Arguments& args) {
@@ -273,7 +351,6 @@ class LoggingNativeHandler : public NativeHandler {
       }
     }
     DCHECK(check_value) << error_message;
-    LOG(WARNING) << error_message;
     return v8::Undefined();
   }
 
@@ -305,20 +382,6 @@ void InstallWebstoreBindings(ModuleSystem* module_system,
                               "chromeHiddenWebstore");
 }
 
-static v8::Handle<v8::Object> GetOrCreateChrome(
-    v8::Handle<v8::Context> context) {
-  v8::Handle<v8::String> chrome_string(v8::String::New("chrome"));
-  v8::Handle<v8::Object> global(context->Global());
-  v8::Handle<v8::Value> chrome(global->Get(chrome_string));
-  if (chrome.IsEmpty() || chrome->IsUndefined()) {
-    v8::Handle<v8::Object> chrome_object(v8::Object::New());
-    global->Set(chrome_string, chrome_object);
-    return chrome_object;
-  }
-  CHECK(chrome->IsObject());
-  return chrome->ToObject();
-}
-
 }  // namespace
 
 Dispatcher::Dispatcher()
@@ -339,7 +402,7 @@ Dispatcher::Dispatcher()
   }
 
   user_script_slave_.reset(new UserScriptSlave(&extensions_));
-  request_sender_.reset(new RequestSender(this, &v8_context_set_));
+  request_sender_.reset(new RequestSender(this));
   PopulateSourceMap();
   PopulateLazyBindingsMap();
 }
@@ -564,62 +627,136 @@ bool Dispatcher::AllowScriptExtension(WebFrame* frame,
   return true;
 }
 
+v8::Handle<v8::Object> Dispatcher::GetOrCreateObject(
+    v8::Handle<v8::Object> object,
+    const std::string& field) {
+  v8::HandleScope handle_scope;
+  v8::Handle<v8::String> key = v8::String::New(field.c_str());
+  // This little dance is for APIs that may be unavailable but have available
+  // children. For example, chrome.app can be unavailable, while
+  // chrome.app.runtime is available. The lazy getter for chrome.app must be
+  // deleted, so that there isn't an error when accessing chrome.app.runtime.
+  if (object->Has(key)) {
+    v8::Handle<v8::Value> value = object->Get(key);
+    if (value->IsObject())
+      return handle_scope.Close(v8::Handle<v8::Object>::Cast(value));
+    else
+      object->Delete(key);
+  }
+
+  v8::Handle<v8::Object> new_object = v8::Object::New();
+  object->Set(key, new_object);
+  return handle_scope.Close(new_object);
+}
+
+void Dispatcher::RegisterSchemaGeneratedBindings(
+    ModuleSystem* module_system,
+    ChromeV8Context* context,
+    v8::Handle<v8::Context> v8_context) {
+  std::set<std::string> apis =
+      ExtensionAPI::GetSharedInstance()->GetAllAPINames();
+  for (std::set<std::string>::iterator it = apis.begin();
+       it != apis.end(); ++it) {
+    const std::string& api_name = *it;
+
+    std::vector<std::string> split;
+    base::SplitString(api_name, '.', &split);
+
+    v8::Handle<v8::Object> bind_object = GetOrCreateChrome(v8_context);
+    for (size_t i = 0; i < split.size() - 1; ++i)
+      bind_object = GetOrCreateObject(bind_object, split[i]);
+
+    if (lazy_bindings_map_.find(api_name) != lazy_bindings_map_.end()) {
+      InstallBindings(module_system, v8_context, api_name);
+    } else if (!source_map_.Contains(api_name)) {
+      module_system->RegisterNativeHandler(
+          api_name,
+          scoped_ptr<NativeHandler>(new BindingGeneratingNativeHandler(
+              module_system,
+              api_name,
+              "binding")));
+      module_system->SetNativeLazyField(bind_object,
+                                        split.back(),
+                                        api_name,
+                                        "binding");
+    } else {
+      module_system->SetLazyField(bind_object,
+                                  split.back(),
+                                  api_name,
+                                  "binding");
+    }
+  }
+}
+
 void Dispatcher::RegisterNativeHandlers(ModuleSystem* module_system,
                                         ChromeV8Context* context) {
+  v8::Handle<v8::Context> v8_context = context->v8_context();
+
   module_system->RegisterNativeHandler("event_bindings",
-      scoped_ptr<NativeHandler>(EventBindings::Get(this)));
+      scoped_ptr<NativeHandler>(EventBindings::Create(this, v8_context)));
   module_system->RegisterNativeHandler("miscellaneous_bindings",
-      scoped_ptr<NativeHandler>(MiscellaneousBindings::Get(this)));
+      scoped_ptr<NativeHandler>(MiscellaneousBindings::Get(this, v8_context)));
   module_system->RegisterNativeHandler("apiDefinitions",
-      scoped_ptr<NativeHandler>(new ApiDefinitionsNatives(this)));
+      scoped_ptr<NativeHandler>(new ApiDefinitionsNatives(this, context)));
   module_system->RegisterNativeHandler("sendRequest",
       scoped_ptr<NativeHandler>(
-          new SendRequestNatives(this, request_sender_.get())));
+          new SendRequestNatives(this, request_sender_.get(), context)));
   module_system->RegisterNativeHandler("setIcon",
       scoped_ptr<NativeHandler>(
-          new SetIconNatives(this, request_sender_.get())));
-  module_system->RegisterNativeHandler("contentWatcherNative",
-                                       content_watcher_->MakeNatives());
+          new SetIconNatives(this, request_sender_.get(), context)));
+  module_system->RegisterNativeHandler(
+      "contentWatcherNative",
+      content_watcher_->MakeNatives(v8_context));
 
   // Natives used by multiple APIs.
   module_system->RegisterNativeHandler("file_system_natives",
-      scoped_ptr<NativeHandler>(new FileSystemNatives()));
+      scoped_ptr<NativeHandler>(new FileSystemNatives(v8_context)));
 
   // Custom bindings.
   module_system->RegisterNativeHandler("app",
       scoped_ptr<NativeHandler>(new AppBindings(this, context)));
   module_system->RegisterNativeHandler("app_runtime",
-      scoped_ptr<NativeHandler>(new AppRuntimeCustomBindings()));
+      scoped_ptr<NativeHandler>(
+          new AppRuntimeCustomBindings(this, v8_context)));
   module_system->RegisterNativeHandler("app_window",
-      scoped_ptr<NativeHandler>(new AppWindowCustomBindings(this)));
+      scoped_ptr<NativeHandler>(
+          new AppWindowCustomBindings(this, v8_context)));
   module_system->RegisterNativeHandler("context_menus",
-      scoped_ptr<NativeHandler>(new ContextMenusCustomBindings()));
+      scoped_ptr<NativeHandler>(
+          new ContextMenusCustomBindings(this, v8_context)));
   module_system->RegisterNativeHandler("extension",
       scoped_ptr<NativeHandler>(
-          new ExtensionCustomBindings(this)));
+          new ExtensionCustomBindings(this, v8_context)));
   module_system->RegisterNativeHandler("sync_file_system",
-      scoped_ptr<NativeHandler>(new SyncFileSystemCustomBindings()));
+      scoped_ptr<NativeHandler>(
+          new SyncFileSystemCustomBindings(this, v8_context)));
   module_system->RegisterNativeHandler("file_browser_handler",
-      scoped_ptr<NativeHandler>(new FileBrowserHandlerCustomBindings()));
+      scoped_ptr<NativeHandler>(new FileBrowserHandlerCustomBindings(
+          this, v8_context)));
   module_system->RegisterNativeHandler("file_browser_private",
-      scoped_ptr<NativeHandler>(new FileBrowserPrivateCustomBindings()));
+      scoped_ptr<NativeHandler>(new FileBrowserPrivateCustomBindings(
+          this, v8_context)));
   module_system->RegisterNativeHandler("i18n",
-      scoped_ptr<NativeHandler>(new I18NCustomBindings()));
+      scoped_ptr<NativeHandler>(
+          new I18NCustomBindings(this, v8_context)));
   module_system->RegisterNativeHandler("mediaGalleries",
-      scoped_ptr<NativeHandler>(new MediaGalleriesCustomBindings()));
+      scoped_ptr<NativeHandler>(
+          new MediaGalleriesCustomBindings(this, v8_context)));
   module_system->RegisterNativeHandler("page_actions",
       scoped_ptr<NativeHandler>(
-          new PageActionsCustomBindings(this)));
+          new PageActionsCustomBindings(this, v8_context)));
   module_system->RegisterNativeHandler("page_capture",
-      scoped_ptr<NativeHandler>(new PageCaptureCustomBindings()));
+      scoped_ptr<NativeHandler>(
+          new PageCaptureCustomBindings(this, v8_context)));
   module_system->RegisterNativeHandler("runtime",
       scoped_ptr<NativeHandler>(new RuntimeCustomBindings(this, context)));
   module_system->RegisterNativeHandler("tabs",
-      scoped_ptr<NativeHandler>(new TabsCustomBindings()));
+      scoped_ptr<NativeHandler>(new TabsCustomBindings(this, v8_context)));
   module_system->RegisterNativeHandler("tts",
-      scoped_ptr<NativeHandler>(new TTSCustomBindings()));
+      scoped_ptr<NativeHandler>(new TTSCustomBindings(this, v8_context)));
   module_system->RegisterNativeHandler("web_request",
-      scoped_ptr<NativeHandler>(new WebRequestCustomBindings()));
+      scoped_ptr<NativeHandler>(
+          new WebRequestCustomBindings(this, v8_context)));
   module_system->RegisterNativeHandler("webstore",
       scoped_ptr<NativeHandler>(new WebstoreBindings(this, context)));
 }
@@ -628,11 +765,9 @@ void Dispatcher::PopulateSourceMap() {
   source_map_.RegisterSource("event_bindings", IDR_EVENT_BINDINGS_JS);
   source_map_.RegisterSource("miscellaneous_bindings",
       IDR_MISCELLANEOUS_BINDINGS_JS);
-  source_map_.RegisterSource("schema_generated_bindings",
-      IDR_SCHEMA_GENERATED_BINDINGS_JS);
   source_map_.RegisterSource("json", IDR_JSON_JS);
   source_map_.RegisterSource("json_schema", IDR_JSON_SCHEMA_JS);
-  source_map_.RegisterSource("apitest", IDR_EXTENSION_APITEST_JS);
+  source_map_.RegisterSource("test", IDR_TEST_CUSTOM_BINDINGS_JS);
 
   // Libraries.
   source_map_.RegisterSource("contentWatcher", IDR_CONTENT_WATCHER_JS);
@@ -701,13 +836,16 @@ void Dispatcher::PopulateSourceMap() {
   source_map_.RegisterSource("webRequestInternal",
                              IDR_WEB_REQUEST_INTERNAL_CUSTOM_BINDINGS_JS);
   source_map_.RegisterSource("webstore", IDR_WEBSTORE_CUSTOM_BINDINGS_JS);
+  source_map_.RegisterSource("binding", IDR_BINDING_JS);
 
   // Platform app sources that are not API-specific..
   source_map_.RegisterSource("tagWatcher", IDR_TAG_WATCHER_JS);
-  source_map_.RegisterSource("webview", IDR_WEB_VIEW_JS);
-  source_map_.RegisterSource("webview.experimental",
+  // Note: webView not webview so that this doesn't interfere with the
+  // chrome.webview API bindings.
+  source_map_.RegisterSource("webView", IDR_WEB_VIEW_JS);
+  source_map_.RegisterSource("webViewExperimental",
                              IDR_WEB_VIEW_EXPERIMENTAL_JS);
-  source_map_.RegisterSource("denyWebview", IDR_WEB_VIEW_DENY_JS);
+  source_map_.RegisterSource("denyWebView", IDR_WEB_VIEW_DENY_JS);
   source_map_.RegisterSource("platformApp", IDR_PLATFORM_APP_JS);
   source_map_.RegisterSource("injectAppTitlebar", IDR_INJECT_APP_TITLEBAR_JS);
 }
@@ -779,15 +917,22 @@ void Dispatcher::DidCreateScriptContext(
 
   RegisterNativeHandlers(module_system.get(), context);
 
-  v8::Isolate* isolate = v8_context->GetIsolate();
+  module_system->RegisterNativeHandler("chrome",
+      scoped_ptr<NativeHandler>(new ChromeNativeHandler(v8_context)));
   module_system->RegisterNativeHandler("chrome_hidden",
-      scoped_ptr<NativeHandler>(new ChromeHiddenNativeHandler(isolate)));
+      scoped_ptr<NativeHandler>(new ChromeHiddenNativeHandler(v8_context)));
   module_system->RegisterNativeHandler("print",
-      scoped_ptr<NativeHandler>(new PrintNativeHandler(isolate)));
+      scoped_ptr<NativeHandler>(new PrintNativeHandler(v8_context)));
   module_system->RegisterNativeHandler("lazy_background_page",
-      scoped_ptr<NativeHandler>(new LazyBackgroundPageNativeHandler(this)));
+      scoped_ptr<NativeHandler>(
+          new LazyBackgroundPageNativeHandler(this, v8_context)));
   module_system->RegisterNativeHandler("logging",
-      scoped_ptr<NativeHandler>(new LoggingNativeHandler(isolate)));
+      scoped_ptr<NativeHandler>(new LoggingNativeHandler(v8_context)));
+  module_system->RegisterNativeHandler("schema_registry",
+      scoped_ptr<NativeHandler>(
+          new SchemaRegistryNativeHandler(v8_schema_registry(), v8_context)));
+  module_system->RegisterNativeHandler("v8_context",
+      scoped_ptr<NativeHandler>(new V8ContextNativeHandler(context)));
 
   int manifest_version = extension ? extension->manifest_version() : 1;
   bool send_request_disabled =
@@ -795,7 +940,7 @@ void Dispatcher::DidCreateScriptContext(
        BackgroundInfo::HasLazyBackgroundPage(extension));
   module_system->RegisterNativeHandler("process",
       scoped_ptr<NativeHandler>(new ProcessInfoNativeHandler(
-          this, context->GetExtensionID(),
+          this, v8_context, context->GetExtensionID(),
           context->GetContextTypeDescription(),
           ChromeRenderProcessObserver::is_incognito_process(),
           manifest_version, send_request_disabled)));
@@ -811,25 +956,20 @@ void Dispatcher::DidCreateScriptContext(
       InstallBindings(module_system.get(), v8_context, "app");
       InstallBindings(module_system.get(), v8_context, "webstore");
       break;
-
     case Feature::BLESSED_EXTENSION_CONTEXT:
     case Feature::UNBLESSED_EXTENSION_CONTEXT:
     case Feature::CONTENT_SCRIPT_CONTEXT: {
+      if (extension && !extension->is_platform_app())
+        module_system->Require("miscellaneous_bindings");
       module_system->Require("json");  // see paranoid comment in json.js
-      module_system->Require("miscellaneous_bindings");
-      module_system->Require("schema_generated_bindings");
-      module_system->Require("apitest");
 
       // TODO(kalman): move this code back out of the switch and execute it
       // regardless of |context_type|. ExtensionAPI knows how to return the
       // correct APIs, however, until it doesn't have a 2MB overhead we can't
       // load it in every process.
-      const std::set<std::string>& apis = context->GetAvailableExtensionAPIs();
-      for (std::set<std::string>::const_iterator i = apis.begin();
-           i != apis.end(); ++i) {
-        InstallBindings(module_system.get(), v8_context, *i);
-      }
-
+      RegisterSchemaGeneratedBindings(module_system.get(),
+                                      context,
+                                      v8_context);
       break;
     }
   }
@@ -839,11 +979,14 @@ void Dispatcher::DidCreateScriptContext(
     module_system->Require("platformApp");
 
   if (context_type == Feature::BLESSED_EXTENSION_CONTEXT) {
-    bool has_permission = extension->HasAPIPermission(APIPermission::kWebView);
-    module_system->Require(has_permission ? "webview" : "denyWebview");
-    if (has_permission &&
-        Feature::GetCurrentChannel() <= chrome::VersionInfo::CHANNEL_DEV) {
-      module_system->Require("webview.experimental");
+    // Note: setting up the WebView class here, not the chrome.webview API.
+    // The API will be automatically set up when first used.
+    if (extension->HasAPIPermission(APIPermission::kWebView)) {
+      module_system->Require("webView");
+      if (Feature::GetCurrentChannel() <= chrome::VersionInfo::CHANNEL_DEV)
+        module_system->Require("webViewExperimental");
+    } else {
+      module_system->Require("denyWebView");
     }
   }
 
@@ -885,6 +1028,8 @@ void Dispatcher::WillReleaseScriptContext(
     return;
 
   context->DispatchOnUnloadEvent();
+  // TODO(kalman): add an invalidation observer interface to ChromeV8Context.
+  request_sender_->InvalidateContext(context);
 
   v8_context_set_.Remove(context);
   VLOG(1) << "Num tracked contexts: " << v8_context_set_.size();
@@ -1129,9 +1274,8 @@ void Dispatcher::OnExtensionResponse(int request_id,
   request_sender_->HandleResponse(request_id, success, response, error);
 }
 
-bool Dispatcher::CheckCurrentContextAccessToExtensionAPI(
-    const std::string& function_name) const {
-  ChromeV8Context* context = v8_context_set().GetCurrent();
+bool Dispatcher::CheckContextAccessToExtensionAPI(
+    const std::string& function_name, ChromeV8Context* context) const {
   if (!context) {
     DLOG(ERROR) << "Not in a v8::Context";
     return false;