make global_instance_ more strict

Fix a bug where global_instance_ was not set to zero.
Fix MockRenderThread to call OnChannelClosing properly.

Review URL: https://codereview.chromium.org/169063003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@252078 0039d316-1c4b-4281-b951-d872f2087c98

chrome/renderer/media/cast_ipc_dispatcher.cc

@@ -20,8 +20,7 @@ CastIPCDispatcher::CastIPCDispatcher(
 
 CastIPCDispatcher::~CastIPCDispatcher() {
   DCHECK(io_message_loop_->BelongsToCurrentThread());
-  // Unfortunately, you do not always get a OnFilterRemoved call.
-  global_instance_ = NULL;
+  DCHECK(!global_instance_);
 }
 
 CastIPCDispatcher* CastIPCDispatcher::Get() {
@@ -74,7 +73,6 @@ void CastIPCDispatcher::OnFilterRemoved() {
 void CastIPCDispatcher::OnChannelClosing() {
   DCHECK(io_message_loop_->BelongsToCurrentThread());
   DCHECK_EQ(this, global_instance_);
-  channel_ = NULL;
 }
 
 void CastIPCDispatcher::OnReceivedPacket(

content/public/test/mock_render_thread.cc

@@ -26,6 +26,11 @@ MockRenderThread::MockRenderThread()
 }
 
 MockRenderThread::~MockRenderThread() {
+  while (!filters_.empty()) {
+    scoped_refptr<IPC::ChannelProxy::MessageFilter> filter = filters_.back();
+    filters_.pop_back();
+    filter->OnFilterRemoved();
+  }
 }
 
 void MockRenderThread::VerifyRunJavaScriptMessageSend(