support multiple log message handlers in base/logging.h

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 51c2868899c077360575fbf89cab0518e99bc7a0..0394165c9698e85de5da787f491a9777eac8996e 100644
--- a/content/gpu/gpu_main.cc
+++ b/content/gpu/gpu_main.cc
@@ -102,13 +102,12 @@ 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& 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) + "):";
   deferred_messages.Get().push(
-      new GpuHostMsg_OnLogMessage(severity, header, message));
+      new GpuHostMsg_OnLogMessage(severity, header, str));
   return false;
 }
 
@@ -191,7 +190,7 @@ int GpuMain(const MainFunctionParams& parameters) {
 
 #endif
 
-  logging::SetLogMessageHandler(GpuProcessLogMessageHandler);
+  logging::AddLogMessageHandler(GpuProcessLogMessageHandler);
 
 #if defined(OS_WIN)
   // OK to use default non-UI message loop because all GPU windows run on
@@ -249,7 +248,7 @@ int GpuMain(const MainFunctionParams& parameters) {
   const bool init_success = gpu_init.InitializeAndStartSandbox(command_line);
   const bool dead_on_arrival = !init_success;
 
-  logging::SetLogMessageHandler(NULL);
+  logging::RemoveLogMessageHandler(GpuProcessLogMessageHandler);
   GetContentClient()->SetGpuInfo(gpu_init.gpu_info());
 
   std::unique_ptr<gpu::GpuMemoryBufferFactory> gpu_memory_buffer_factory;