Hook up RendererMediaSessionManager with browser side

content/renderer/media/android/renderer_media_session_manager.cc

Index: content/renderer/media/android/renderer_media_session_manager.cc
diff --git a/content/renderer/media/android/renderer_media_session_manager.cc b/content/renderer/media/android/renderer_media_session_manager.cc
index c39c0dce2eefb66c02a5da977e8228ee2f888853..5ad26de46b9e2b08f716e2c561a3b853978f43e2 100644
--- a/content/renderer/media/android/renderer_media_session_manager.cc
+++ b/content/renderer/media/android/renderer_media_session_manager.cc
@@ -5,6 +5,8 @@
 #include "content/renderer/media/android/renderer_media_session_manager.h"
 
 #include "base/logging.h"
+#include "content/common/media/media_session_messages_android.h"
+#include "content/public/renderer/render_thread.h"
 #include "content/renderer/media/android/webmediasession_android.h"
 
 namespace content {
@@ -22,6 +24,16 @@ RendererMediaSessionManager::~RendererMediaSessionManager() {
          "destroyed only after all media sessions are destroyed.";
 }
 
+bool RendererMediaSessionManager::OnMessageReceived(const IPC::Message& msg) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(RendererMediaSessionManager, msg)
+    IPC_MESSAGE_HANDLER(MediaSessionMsg_DidActivate, OnDidActivate)
+    IPC_MESSAGE_HANDLER(MediaSessionMsg_DidDeactivate, OnDidDeactivate)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
 int RendererMediaSessionManager::RegisterMediaSession(
     WebMediaSessionAndroid* session) {
   sessions_[next_session_id_] = session;
@@ -32,4 +44,36 @@ void RendererMediaSessionManager::UnregisterMediaSession(int session_id) {
   sessions_.erase(session_id);
 }
 
+void RendererMediaSessionManager::Activate(int session_id, int request_id) {
+  Send(new MediaSessionHostMsg_Activate(routing_id(), session_id, request_id));
+}
+
+void RendererMediaSessionManager::Deactivate(int session_id, int request_id) {
+  Send(
+      new MediaSessionHostMsg_Deactivate(routing_id(), session_id, request_id));
+}
+
+void RendererMediaSessionManager::OnDidActivate(int session_id,
+                                                int request_id,
+                                                bool success) {
+  std::map<int, WebMediaSessionAndroid*>::iterator iter =
+      sessions_.find(session_id);
+
+  if (iter == sessions_.end())
+    return;

[philipj_slow, 2015/12/04 14:01:04]

This is probably where we will end up if the MediaSession is GC'd while the
activate request is in flight on the browser side. That would leave the promise
mysteriously unresolved, it seems. (If we later add a statechange event to
MediaSession, that would make the problem slightly worse.)

Probably need to DCHECK something here, and also make MediaSession an
ActiveDOMObject that cannot be GC'd while WebMediaSession::hasPendingCallbacks()
or similar returns true.

[davve, 2015/12/04 14:52:54]

Adding  WebMediaSession::hasPendingCallbacks() seems to be worthwhile.

I also add a test for handling messages for unknown session, which also would
trigger this code-path. Unless we get a different consensus on what type of
IPC-simulations to test, I can't add a DCHECK().

+
+  iter->second->OnDidActivate(request_id, success);
+}
+
+void RendererMediaSessionManager::OnDidDeactivate(int session_id,
+                                                  int request_id) {
+  std::map<int, WebMediaSessionAndroid*>::iterator iter =
+      sessions_.find(session_id);
+
+  if (iter == sessions_.end())
+    return;
+
+  iter->second->OnDidDeactivate(request_id);
+}
+
 }  // namespace content