Make app_custom_bindings.js lazily evaluated so it doesn't execute on every page load.

chrome/renderer/module_system.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/renderer/module_system.h"
 
 #include "base/bind.h"
 
 namespace {
 
@@ skipping 11 matching lines @@
   RouteFunction("requireNative",
       base::Bind(&ModuleSystem::GetNative, base::Unretained(this)));
 
   v8::Handle<v8::Object> global(v8::Context::GetCurrent()->Global());
   global->SetHiddenValue(v8::String::New("modules"), v8::Object::New());
 }
 
 ModuleSystem::~ModuleSystem() {
 }
 
+ModuleSystem::NativesEnabledScope::NativesEnabledScope(
+    ModuleSystem* module_system)
+    : module_system_(module_system) {
+  module_system_->set_natives_enabled(true);

[not at google - send to devlin, 2012/03/25 22:42:58]

This won't work with nested "natives enabled" scopes. Making it work with nested
scoped would be a bit of a pain, you'd need to make natives enabled a counter
rather than a boolean or something.

I would say "fine to just CHECK that natives is disabled" and that would be
equivalent if GetterRouter below can't be called while natives is enabled, but
is that true? What if an extension references "chrome.app" in its startup
sequence?

[koz (OOO until 15th September), 2012/03/26 01:36:09]

Good point. I've made it a counter and removed the set_natives_enabled() method.

+}
+
+ModuleSystem::NativesEnabledScope::~NativesEnabledScope() {
+  module_system_->set_natives_enabled(false);
+}
+
 void ModuleSystem::Require(const std::string& module_name) {
   v8::HandleScope handle_scope;
   RequireForJsInner(v8::String::New(module_name.c_str()));
 }
 
 v8::Handle<v8::Value> ModuleSystem::RequireForJs(const v8::Arguments& args) {
   v8::HandleScope handle_scope;
   v8::Handle<v8::String> module_name = args[0]->ToString();
   return handle_scope.Close(RequireForJsInner(module_name));
 }
@@ skipping 42 matching lines @@
     v8::Local<v8::String> property, const v8::AccessorInfo& info) {
   CHECK(!info.Data().IsEmpty());
   CHECK(info.Data()->IsObject());
   v8::HandleScope handle_scope;
   v8::Handle<v8::Object> parameters = v8::Handle<v8::Object>::Cast(info.Data());
   v8::Handle<v8::Value> module_system_value =
       parameters->Get(v8::String::New(kModuleSystem));
   ModuleSystem* module_system = static_cast<ModuleSystem*>(
       v8::Handle<v8::External>::Cast(module_system_value)->Value());
 
-  v8::Handle<v8::Object> module = module_system->RequireForJsInner(
-      parameters->Get(v8::String::New(kModuleName))->ToString())->ToObject();
+  v8::Handle<v8::Object> module;
+  {
+    NativesEnabledScope scope(module_system);
+    module = module_system->RequireForJsInner(
+        parameters->Get(v8::String::New(kModuleName))->ToString())->ToObject();

[not at google - send to devlin, 2012/03/25 22:42:58]

(see comment above)

[koz (OOO until 15th September), 2012/03/26 01:36:09]

Done.

+  }
 
   v8::Handle<v8::String> field =
       parameters->Get(v8::String::New(kModuleField))->ToString();
 
   return handle_scope.Close(module->Get(field));
 }
 
 void ModuleSystem::SetLazyField(v8::Handle<v8::Object> object,
                                 const std::string& field,
                                 const std::string& module_name,
@@ skipping 43 matching lines @@
   v8::Handle<v8::String> left =
       v8::String::New("(function(require, requireNative, exports) {");
   v8::Handle<v8::String> right = v8::String::New("\n})");
   return handle_scope.Close(
       v8::String::Concat(left, v8::String::Concat(source, right)));
 }
 
 v8::Handle<v8::Value> ModuleSystem::ThrowException(const std::string& message) {
   return v8::ThrowException(v8::String::New(message.c_str()));
 }