support multiple log message handlers in base/logging.h

content/gpu/gpu_child_thread.cc

Index: content/gpu/gpu_child_thread.cc
diff --git a/content/gpu/gpu_child_thread.cc b/content/gpu/gpu_child_thread.cc
index a1076a99dcf5aa0ac59768c094f6a3d057d3c841..9a16b63b3c6b7189a523d28f586ec383c80a9c61 100644
--- a/content/gpu/gpu_child_thread.cc
+++ b/content/gpu/gpu_child_thread.cc
@@ -61,14 +61,12 @@ static base::LazyInstance<scoped_refptr<ThreadSafeSender> >
     g_thread_safe_sender = LAZY_INSTANCE_INITIALIZER;
 
 bool GpuProcessLogMessageHandler(int severity,
-                                 const char* file, int line,
-                                 size_t message_start,
+                                 const std::string& file,
+                                 int line,
                                  const std::string& str) {
-  std::string header = str.substr(0, message_start);
-  std::string message = str.substr(message_start);
-
+  std::string header = file + "(" + std::to_string(line) + "):";
   g_thread_safe_sender.Get()->Send(
-      new GpuHostMsg_OnLogMessage(severity, header, message));
+      new GpuHostMsg_OnLogMessage(severity, header, str));
 
   return false;
 }
@@ -195,7 +193,8 @@ GpuChildThread::~GpuChildThread() {
 
 void GpuChildThread::Shutdown() {
   ChildThreadImpl::Shutdown();
-  logging::SetLogMessageHandler(NULL);
+  if (!in_browser_process_)
+    logging::RemoveLogMessageHandler(GpuProcessLogMessageHandler);
 }
 
 void GpuChildThread::Init(const base::Time& process_start_time) {
@@ -333,7 +332,7 @@ void GpuChildThread::OnInitialize(const gpu::GpuPreferences& gpu_preferences) {
   // We don't need to pipe log messages if we are running the GPU thread in
   // the browser process.
   if (!in_browser_process_)
-    logging::SetLogMessageHandler(GpuProcessLogMessageHandler);
+    logging::AddLogMessageHandler(GpuProcessLogMessageHandler);
 
   gpu::SyncPointManager* sync_point_manager = nullptr;
   // Note SyncPointManager from ContentGpuClient cannot be owned by this.