Change g_webrtc_logging_delegate from process-level to RenderThread-level

content/renderer/media/webrtc_logging.cc

Index: content/renderer/media/webrtc_logging.cc
diff --git a/content/renderer/media/webrtc_logging.cc b/content/renderer/media/webrtc_logging.cc
index 17e5c5745420d96fcd68aefd64911bdf1f9c5140..204c2c99ab37e62b55a21edb83a3a9bde100ae05 100644
--- a/content/renderer/media/webrtc_logging.cc
+++ b/content/renderer/media/webrtc_logging.cc
@@ -5,19 +5,22 @@
 #include "content/renderer/media/webrtc_logging.h"
 
 #include "base/time/time.h"
+#include "base/lazy_instance.h"
+#include "base/threading/thread_local.h"
 #include "content/public/renderer/webrtc_log_message_delegate.h"
 #include "third_party/webrtc/overrides/webrtc/base/logging.h"
 
 namespace content {
 
-// Shall only be set once and never go back to NULL.
-WebRtcLogMessageDelegate* g_webrtc_logging_delegate = NULL;
+// Shall only be set once within a RenderThread and never go back to NULL.
+base::LazyInstance<base::ThreadLocalPointer<WebRtcLogMessageDelegate> >::Leaky
+    g_webrtc_logging_delegate_tls = LAZY_INSTANCE_INITIALIZER;
 
 void InitWebRtcLoggingDelegate(WebRtcLogMessageDelegate* delegate) {
-  CHECK(!g_webrtc_logging_delegate);
+  CHECK(!g_webrtc_logging_delegate_tls.Pointer()->Get());
   CHECK(delegate);
 
-  g_webrtc_logging_delegate = delegate;
+  g_webrtc_logging_delegate_tls.Pointer()->Set(delegate);
 }
 
 void InitWebRtcLogging() {
@@ -26,8 +29,8 @@ void InitWebRtcLogging() {
 }
 
 void WebRtcLogMessage(const std::string& message) {
-  if (g_webrtc_logging_delegate)
-    g_webrtc_logging_delegate->LogMessage(message);
+  if (g_webrtc_logging_delegate_tls.Pointer()->Get())
+    g_webrtc_logging_delegate_tls.Pointer()->Get()->LogMessage(message);
 }
 
 }  // namespace content