<webview>: First stab at implementing media permission request for guests.

content/renderer/browser_plugin/browser_plugin.cc

Index: content/renderer/browser_plugin/browser_plugin.cc
diff --git a/content/renderer/browser_plugin/browser_plugin.cc b/content/renderer/browser_plugin/browser_plugin.cc
index c0e255ea54eaea7f901d2cfdba5d7b1513a4e55d..76f02435d2b817dc9fcac7512805a1ce5021c88a 100644
--- a/content/renderer/browser_plugin/browser_plugin.cc
+++ b/content/renderer/browser_plugin/browser_plugin.cc
@@ -27,8 +27,8 @@
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebInputEvent.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebPluginContainer.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebPluginParams.h"
-#include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebRect.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebScriptSource.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebRect.h"
 #include "webkit/plugins/sad_plugin.h"
 
 #if defined (OS_WIN)
@@ -54,6 +54,7 @@ const char kEventLoadCommit[] = "loadcommit";
 const char kEventLoadRedirect[] = "loadredirect";
 const char kEventLoadStart[] = "loadstart";
 const char kEventLoadStop[] = "loadstop";
+const char kEventRequestPermission[] = "permissionrequest";
 const char kEventSizeChanged[] = "sizechanged";
 
 // Parameters/properties on events.
@@ -65,9 +66,11 @@ const char kOldURL[] = "oldUrl";
 const char kOldHeight[] = "oldHeight";
 const char kOldWidth[] = "oldWidth";
 const char kPartition[] = "partition";
+const char kPermissionTypeMedia[] = "media";
 const char kPersistPrefix[] = "persist:";
 const char kProcessId[] = "processId";
 const char kReason[] = "reason";
+const char kRequestId[] = "request_id";
 const char kSrc[] = "src";
 const char kURL[] = "url";
 
@@ -664,6 +667,18 @@ void BrowserPlugin::LoadAbort(const GURL& url,
   TriggerEvent(kEventLoadAbort, &props);
 }
 
+void BrowserPlugin::RequestMediaAccess(int request_id) {
+  // TODO(lazyboy): Automatically deny the request if there are no event
+  // listeners for permissionrequest. Right now it is not possible to know about

[Charlie Reis, 2012/12/07 19:16:25]

So what happens now if there's no listeners?  Do we end up with lots of
outstanding requests that are never cleaned up?

Also, how are we handling multiple listeners?  I found our email discussion
("API design question: policy functions") and it seems like we were settling on
requiring all listeners to call allow() to grant the permission.  Is that
possible if we don't know how many listeners there are?

[lazyboy, 2012/12/07 22:50:44]

When there's no listeners, yes we end up with lost/outstanding requests. I am
attempting to figure this out (https://chromiumcodereview.appspot.com/11446071/)
so we automatically deny, but bad thing about that is this code here needs to be
shim aware. The other bad thing is even if we have listeners, we can end up with
outstanding request, if the embedder ignores the event by not calling
allow/deny.

Multiple listeners are not handled in this CL at all. Only the first one to call
allow/deny wins (and that clears the request), so the subsequent calls to
allow/deny are ignored. I am not sure how to approach this yet, webkit doesn't
seem to expose anything about # of event listeners registered.

+  // this info directly from the plugin because the user facing event listeners
+  // are registered on the shim, not on the plugin. Also, there is always one
+  // listener registered on the plugin from the shim.

[Charlie Reis, 2012/12/07 19:16:25]

One permissionrequest listener?  I'm not sure I follow.

[lazyboy, 2012/12/07 22:50:44]

This is the one (and only one) '-internal-permissionrequest' listener attached
to <object> from <webview> shim. This one always gets attached, whether or not
there are actual event listeners registered on the <webview> tag.

Where user facing ones are the one on object (that embedder/developer creates)
<webview>.addEventListener('permissionrequest', functionA);
<webview>.addEventListener('permissionrequest', functionB);
<webview>.addEventListener('permissionrequest', functionC);

+  std::map<std::string, base::Value*> props;
+  props[kReason] = base::Value::CreateStringValue(kPermissionTypeMedia);
+  props[kRequestId] = base::Value::CreateIntegerValue(request_id);
+  TriggerEvent(kEventRequestPermission, &props);
+}
+
 void BrowserPlugin::LoadRedirect(const GURL& old_url,
                                  const GURL& new_url,
                                  bool is_top_level) {
@@ -717,6 +732,14 @@ void BrowserPlugin::SetAcceptTouchEvents(bool accept) {
   }
 }
 
+void BrowserPlugin::RespondMediaAccess(int request_id, bool allow) {
+  browser_plugin_manager()->Send(
+      new BrowserPluginHostMsg_AllowMediaAccess(render_view_->GetRoutingID(),
+                                                instance_id_,
+                                                request_id,
+                                                allow));
+}
+
 WebKit::WebPluginContainer* BrowserPlugin::container() const {
   return container_;
 }