Allow multiple logging::LogMessage{Handler,Listener}s

content/gpu/gpu_main.cc

Index: content/gpu/gpu_main.cc
diff --git a/content/gpu/gpu_main.cc b/content/gpu/gpu_main.cc
index cc326628adae5463536525a2d2c8c478547c1453..4c9e33e48fddd331b937b47111879fc80ca33059 100644
--- a/content/gpu/gpu_main.cc
+++ b/content/gpu/gpu_main.cc
@@ -119,15 +119,14 @@ bool StartSandboxWindows(const sandbox::SandboxInterfaceInfo*);
 base::LazyInstance<GpuChildThread::DeferredMessages> deferred_messages =
     LAZY_INSTANCE_INITIALIZER;
 
-bool GpuProcessLogMessageHandler(int severity,
-                                 const char* file, int line,
-                                 size_t message_start,
-                                 const std::string& str) {
+void GpuProcessLogMessageListener(int severity,
+                                  const char* file, int line,
+                                  size_t message_start,
+                                  const std::string& str) {
   std::string header = str.substr(0, message_start);
   std::string message = str.substr(message_start);
   deferred_messages.Get().push(
       new GpuHostMsg_OnLogMessage(severity, header, message));
-  return false;
 }
 
 }  // namespace anonymous
@@ -165,7 +164,7 @@ int GpuMain(const MainFunctionParams& parameters) {
 
 #endif
 
-  logging::SetLogMessageHandler(GpuProcessLogMessageHandler);
+  logging::AddLogMessageListener(GpuProcessLogMessageListener);
 
   if (command_line.HasSwitch(switches::kSupportsDualGpus)) {
     std::string types = command_line.GetSwitchValueASCII(
@@ -384,7 +383,7 @@ int GpuMain(const MainFunctionParams& parameters) {
     dead_on_arrival = true;
   }
 
-  logging::SetLogMessageHandler(NULL);
+  logging::RemoveLogMessageListener(GpuProcessLogMessageListener);
 
   std::unique_ptr<gpu::GpuMemoryBufferFactory> gpu_memory_buffer_factory;
   if (gpu::GetNativeGpuMemoryBufferType() != gfx::EMPTY_BUFFER)