Implement browser-side logging to WebRtc log

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index 317f979b5e832f404e5e2819a7f67d8231c3f5fc..b8fd330176aec086227fd860148883a689b8c233 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -1520,6 +1520,21 @@ void RenderProcessHostImpl::DisableAecDump() {
       base::Bind(&RenderProcessHostImpl::SendDisableAecDumpToRenderer,
                  weak_factory_.GetWeakPtr()));
 }
+
+void RenderProcessHostImpl::SetWebRtcLogMessageCallback(
+    base::Callback<void(const std::string&)> callback) {
+  DCHECK(webrtc_log_message_callback_.is_null());
+  webrtc_log_message_callback_ = callback;
+}
+
+void RenderProcessHostImpl::WebRtcLogMessage(const std::string& message) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  if (!webrtc_log_message_callback_.is_null()) {
+    BrowserThread::PostTask(BrowserThread::IO,
+                            FROM_HERE,
+                            base::Bind(webrtc_log_message_callback_, message));

[jam, 2014/01/17 05:47:44]

how do we guarantee that the callback is valid on the IO thread? RPH is used on
the UI thread, so it's best if we can make the lifetime of the callback valid
just as long which means calling it on the UI thread

[vrk (LEFT CHROMIUM), 2014/01/22 02:25:42]

OK, yeah that makes sense. Moved the thread hop to WebRtcLogMessageHost.

+  };
+}
 #endif
 
 IPC::ChannelProxy* RenderProcessHostImpl::GetChannel() {