Let Flash join and be controlled by media session

content/browser/web_contents/web_contents_impl.h

Index: content/browser/web_contents/web_contents_impl.h
diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
index 4cc0c5bc1e2e1d7013ff2b7530738a287958566f..370f1e4f993e3005df151e9f88dbd492ce357feb 100644
--- a/content/browser/web_contents/web_contents_impl.h
+++ b/content/browser/web_contents/web_contents_impl.h
@@ -63,6 +63,7 @@ class JavaScriptDialogManager;
 class LoaderIOThreadNotifier;
 class ManifestManagerHost;
 class MediaWebContentsObserver;
+class PepperWebContentsObserver;
 class PluginContentOriginWhitelist;
 class PowerSaveBlocker;
 class RenderViewHost;
@@ -742,6 +743,12 @@ class CONTENT_EXPORT WebContentsImpl
     return media_web_contents_observer_.get();
   }
 
+#if defined(ENABLE_PLUGINS)
+  PepperWebContentsObserver* pepper_web_contents_observer() {
+    return pepper_web_contents_observer_.get();
+  }
+#endif  // defined(ENABLE_PLUGINS)
+
   // Update the web contents visibility.
   void UpdateWebContentsVisibility(bool visible);
 
@@ -944,8 +951,8 @@ class CONTENT_EXPORT WebContentsImpl
                    const base::ListValue& args);
   void OnUpdatePageImportanceSignals(const PageImportanceSignals& signals);
 #if defined(ENABLE_PLUGINS)
-  void OnPepperInstanceCreated();
-  void OnPepperInstanceDeleted();
+  void OnPepperInstanceCreated(int32_t pp_instance);
+  void OnPepperInstanceDeleted(int32_t pp_instance);
   void OnPepperPluginHung(int plugin_child_id,
                           const base::FilePath& path,
                           bool is_hung);
@@ -1383,6 +1390,11 @@ class CONTENT_EXPORT WebContentsImpl
   // Manages media players, CDMs, and power save blockers for media.
   std::unique_ptr<MediaWebContentsObserver> media_web_contents_observer_;
 
+#if defined(ENABLE_PLUGINS)
+  // Observer for pepper creation, deletion and playback.
+  std::unique_ptr<PepperWebContentsObserver> pepper_web_contents_observer_;

[jochen (gone - plz use gerrit), 2016/06/27 11:47:11]

have you considered inlining this class in web contents? every observer adds
some overhead to each callback, whether it's implemented or not

[Zhiqiang Zhang (Slow), 2016/06/28 18:53:24]

I made PepperWebContentsObserver not inheriting from WebContentsObserver (also
renamed as PepperPlaybackObserver). Then I delegate the call from
WebContentsImpl to PepperPlaybackObserver. Please see the diff.

Hope this is what you expected. Tell me if I'm wrong.

+#endif  // defined(ENABLE_PLUGINS)
+
   std::unique_ptr<RenderWidgetHostInputEventRouter> rwh_input_event_router_;
 
   PageImportanceSignals page_importance_signals_;