Revert 272540 "Revert 272504 "Destroy all rtc peer connection ha..."

The original change was not a root cause of the problem.
sheriffs are looking into other possible causes.

Meanwhile I am getting the change back in.

> Revert 272504 "Destroy all rtc peer connection handlers before s..."
> 
> On Win7 Tests (dbg)(2) these tests
> 
> FocusElementCallsFocusedNodeChanged
> GetCompositionCharacterBoundsTest
> MessageOrderInDidChangeSelection
> OnExtendSelectionAndDelete
> OnImeTypeChanged
> OnSetTextDirection
> SendCandidateWindowEvents
> SetEditableSelectionAndComposition
> 
> fail with timeout.
> http://build.chromium.org/p/chromium.win/builders/Win7%20Tests%20%28dbg%29%282%29/builds/21101/steps/content_browsertests/logs/stdio
> 
> > Destroy all rtc peer connection handlers before shutting down blink
> > 
> > The connection handlers will otherwise continue to call into blink which
> > is bound to crash after it was shut down.
> > 
> > BUG=337572
> > R=perkj@chromium.org,adamk@chromium.org
> > 
> > Review URL: https://codereview.chromium.org/292163002
> 
> TBR=jochen@chromium.org
> 
> Review URL: https://codereview.chromium.org/296213007

TBR=vasilii@chromium.org,jochen@chromium.org

Review URL: https://codereview.chromium.org/293253003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@272604 0039d316-1c4b-4281-b951-d872f2087c98

content/renderer/media/rtc_peer_connection_handler.cc

@@ -10,6 +10,7 @@
 
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
+#include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram.h"
@@ -317,6 +318,8 @@ void LocalRTCStatsResponse::addStatistic(size_t report,
   impl_.addStatistic(report, name, value);
 }
 
+namespace {
+
 class PeerConnectionUMAObserver : public webrtc::UMAObserver {
  public:
   PeerConnectionUMAObserver() {}
@@ -351,6 +354,11 @@ class PeerConnectionUMAObserver : public webrtc::UMAObserver {
   }
 };
 
+base::LazyInstance<std::set<RTCPeerConnectionHandler*> >::Leaky
+    g_peer_connection_handlers = LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
 RTCPeerConnectionHandler::RTCPeerConnectionHandler(
     blink::WebRTCPeerConnectionHandlerClient* client,
     PeerConnectionDependencyFactory* dependency_factory)
@@ -359,9 +367,11 @@ RTCPeerConnectionHandler::RTCPeerConnectionHandler(
       frame_(NULL),
       peer_connection_tracker_(NULL),
       num_data_channels_created_(0) {
+  g_peer_connection_handlers.Get().insert(this);
 }
 
 RTCPeerConnectionHandler::~RTCPeerConnectionHandler() {
+  g_peer_connection_handlers.Get().erase(this);
   if (peer_connection_tracker_)
     peer_connection_tracker_->UnregisterPeerConnection(this);
   STLDeleteValues(&remote_streams_);
@@ -370,6 +380,18 @@ RTCPeerConnectionHandler::~RTCPeerConnectionHandler() {
       "WebRTC.NumDataChannelsPerPeerConnection", num_data_channels_created_);
 }
 
+// static
+void RTCPeerConnectionHandler::DestructAllHandlers() {
+  std::set<RTCPeerConnectionHandler*> handlers(
+      g_peer_connection_handlers.Get().begin(),
+      g_peer_connection_handlers.Get().end());
+  for (std::set<RTCPeerConnectionHandler*>::iterator handler = handlers.begin();
+       handler != handlers.end();
+       ++handler) {
+    (*handler)->client_->releasePeerConnectionHandler();
+  }
+}
+
 void RTCPeerConnectionHandler::associateWithFrame(blink::WebFrame* frame) {
   DCHECK(frame);
   frame_ = frame;

content/renderer/media/rtc_peer_connection_handler.h

@@ -88,6 +88,9 @@ class CONTENT_EXPORT RTCPeerConnectionHandler
       PeerConnectionDependencyFactory* dependency_factory);
   virtual ~RTCPeerConnectionHandler();
 
+  // Destroy all existing RTCPeerConnectionHandler objects.
+  static void DestructAllHandlers();
+
   void associateWithFrame(blink::WebFrame* frame);
 
   // Initialize method only used for unit test.

content/renderer/render_thread_impl.cc

@@ -79,6 +79,7 @@
 #include "content/renderer/media/midi_message_filter.h"
 #include "content/renderer/media/peer_connection_tracker.h"
 #include "content/renderer/media/renderer_gpu_video_accelerator_factories.h"
+#include "content/renderer/media/rtc_peer_connection_handler.h"
 #include "content/renderer/media/video_capture_impl_manager.h"
 #include "content/renderer/media/video_capture_message_filter.h"
 #include "content/renderer/media/webrtc/peer_connection_dependency_factory.h"
@@ -534,6 +535,8 @@ void RenderThreadImpl::Shutdown() {
   audio_message_filter_ = NULL;
 
 #if defined(ENABLE_WEBRTC)
+  RTCPeerConnectionHandler::DestructAllHandlers();
+
   peer_connection_factory_.reset();
 #endif
   RemoveFilter(vc_manager_->video_capture_message_filter());