Gave two kClassIdentifiers unique names

In jumbo builds several cc files are compiled in the same
translation unit and then the different kClassIdentifier
symbols clashed. This renames them to
kPeerConnectionRemoteTrackIdentifier
and
kProcessedLocalAudioSourceIdentifier

Bug: 746953
Change-Id: I7fe95ebbef69f4dd3b47258417cc917ba441dd91
Reviewed-on: https://chromium-review.googlesource.com/822191Reviewed-by: Sergey Ulanov <sergeyu@chromium.org>
Commit-Queue: Daniel Bratell <bratell@opera.com>
Cr-Commit-Position: refs/heads/master@{#524029}

content/renderer/media/webrtc/peer_connection_remote_audio_source.cc

@@ -12,7 +12,8 @@ namespace content {
 
 namespace {
 // Used as an identifier for the down-casters.
-void* const kClassIdentifier = const_cast<void**>(&kClassIdentifier);
+void* const kPeerConnectionRemoteTrackIdentifier =
+    const_cast<void**>(&kPeerConnectionRemoteTrackIdentifier);
 }  // namespace
 
 PeerConnectionRemoteAudioTrack::PeerConnectionRemoteAudioTrack(
@@ -33,7 +34,8 @@ PeerConnectionRemoteAudioTrack::~PeerConnectionRemoteAudioTrack() {
 // static
 PeerConnectionRemoteAudioTrack* PeerConnectionRemoteAudioTrack::From(
     MediaStreamAudioTrack* track) {
-  if (track && track->GetClassIdentifier() == kClassIdentifier)
+  if (track &&
+      track->GetClassIdentifier() == kPeerConnectionRemoteTrackIdentifier)
     return static_cast<PeerConnectionRemoteAudioTrack*>(track);
   return nullptr;
 }
@@ -54,7 +56,7 @@ void PeerConnectionRemoteAudioTrack::SetEnabled(bool enabled) {
 }
 
 void* PeerConnectionRemoteAudioTrack::GetClassIdentifier() const {
-  return kClassIdentifier;
+  return kPeerConnectionRemoteTrackIdentifier;
 }
 
 PeerConnectionRemoteAudioSource::PeerConnectionRemoteAudioSource(

content/renderer/media/webrtc/processed_local_audio_source.cc

@@ -26,7 +26,8 @@ namespace content {
 
 namespace {
 // Used as an identifier for ProcessedLocalAudioSource::From().
-void* const kClassIdentifier = const_cast<void**>(&kClassIdentifier);
+void* const kProcessedLocalAudioSourceIdentifier =
+    const_cast<void**>(&kProcessedLocalAudioSourceIdentifier);
 }  // namespace
 
 ProcessedLocalAudioSource::ProcessedLocalAudioSource(
@@ -55,13 +56,14 @@ ProcessedLocalAudioSource::~ProcessedLocalAudioSource() {
 // static
 ProcessedLocalAudioSource* ProcessedLocalAudioSource::From(
     MediaStreamAudioSource* source) {
-  if (source && source->GetClassIdentifier() == kClassIdentifier)
+  if (source &&
+      source->GetClassIdentifier() == kProcessedLocalAudioSourceIdentifier)
     return static_cast<ProcessedLocalAudioSource*>(source);
   return nullptr;
 }
 
 void* ProcessedLocalAudioSource::GetClassIdentifier() const {
-  return kClassIdentifier;
+  return kProcessedLocalAudioSourceIdentifier;
 }
 
 bool ProcessedLocalAudioSource::EnsureSourceIsStarted() {