[chrome.displaySource] Session notification improvements

extensions/renderer/display_source_custom_bindings.h

Index: extensions/renderer/display_source_custom_bindings.h
diff --git a/extensions/renderer/display_source_custom_bindings.h b/extensions/renderer/display_source_custom_bindings.h
index 199f199b4663e968a780d31738b54c93f1c704b9..a7a36ab977ab5552db5894e6c3e72b9816a036d3 100644
--- a/extensions/renderer/display_source_custom_bindings.h
+++ b/extensions/renderer/display_source_custom_bindings.h
@@ -29,7 +29,16 @@ class DisplaySourceCustomBindings : public ObjectBackedNativeHandler {
       const v8::FunctionCallbackInfo<v8::Value>& args);
   void TerminateSession(
       const v8::FunctionCallbackInfo<v8::Value>& args);
-
+  // Call completion callbacks.
+  void CallSessionStartedCallback(
+      int sink_id,
+      const std::string& error_message = std::string());
+  void CallSessionTerminatedCallback(
+      int sink_id,
+      const std::string& error_message = std::string());
+  void CallCompletionCallback(const v8::Global<v8::Function>& callback,
+                              const std::string& error_message);
+  // Dispatch events
   void DispatchSessionStarted(int sink_id) const;
   void DispatchSessionTerminated(int sink_id) const;
   void DispatchSessionError(int sink_id,
@@ -46,6 +55,8 @@ class DisplaySourceCustomBindings : public ObjectBackedNativeHandler {
   DisplaySourceSession* GetDisplaySession(int sink_id) const;
 
   std::map<int, scoped_ptr<DisplaySourceSession>> session_map_;
+  std::map<int, v8::Global<v8::Function>> session_started_cb_map_;
+  std::map<int, v8::Global<v8::Function>> session_finished_cb_map_;
   base::WeakPtrFactory<DisplaySourceCustomBindings> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DisplaySourceCustomBindings);