gpu: Use mojom API for recording log messages to the host.

services/ui/gpu/gpu_service.cc

Index: services/ui/gpu/gpu_service.cc
diff --git a/services/ui/gpu/gpu_service.cc b/services/ui/gpu/gpu_service.cc
index 75a81a656cc896852571152417eac520c40b91e7..948353c70e5ef2cbb6a08bc8bb97f43637bb832a 100644
--- a/services/ui/gpu/gpu_service.cc
+++ b/services/ui/gpu/gpu_service.cc
@@ -6,6 +6,7 @@
 
 #include "base/bind.h"
 #include "base/debug/crash_logging.h"
+#include "base/lazy_instance.h"
 #include "base/memory/shared_memory.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
@@ -42,6 +43,23 @@
 
 namespace ui {
 
+namespace {
+
+static base::LazyInstance<base::Callback<
+    void(int severity, size_t message_start, const std::string& message)>>::
+    Leaky g_log_callback = LAZY_INSTANCE_INITIALIZER;
+
+bool GpuLogMessageHandler(int severity,
+                          const char* file,
+                          int line,
+                          size_t message_start,
+                          const std::string& message) {
+  g_log_callback.Get().Run(severity, message_start, message);
+  return false;
+}
+
+}  // namespace
+
 GpuService::GpuService(const gpu::GPUInfo& gpu_info,
                        std::unique_ptr<gpu::GpuWatchdogThread> watchdog_thread,
                        gpu::GpuMemoryBufferFactory* gpu_memory_buffer_factory,
@@ -57,6 +75,9 @@ GpuService::GpuService(const gpu::GPUInfo& gpu_info,
       sync_point_manager_(nullptr) {}
 
 GpuService::~GpuService() {
+  logging::SetLogMessageHandler(nullptr);
+  g_log_callback.Get() =
+      base::Callback<void(int, size_t, const std::string&)>();
   bindings_.CloseAllBindings();
   media_gpu_channel_manager_.reset();
   gpu_channel_manager_.reset();
@@ -87,6 +108,15 @@ void GpuService::InitializeWithHost(mojom::GpuHostPtr gpu_host,
   gpu_host->DidInitialize(gpu_info_);
   gpu_host_ =
       mojom::ThreadSafeGpuHostPtr::Create(gpu_host.PassInterface(), io_runner_);
+  if (!in_host_process_) {
+    // The global callback is reset from the dtor. So Unretained() here is safe.
+    // Note that the callback can be called from any thread. Consequently, the
+    // callback cannot use a WeakPtr.
+    g_log_callback.Get() =
+        base::Bind(&GpuService::RecordLogMessage, base::Unretained(this));
+    logging::SetLogMessageHandler(GpuLogMessageHandler);
+  }
+
   sync_point_manager_ = sync_point_manager;
   if (!sync_point_manager_) {
     owned_sync_point_manager_ = base::MakeUnique<gpu::SyncPointManager>();
@@ -111,6 +141,14 @@ void GpuService::Bind(mojom::GpuServiceRequest request) {
   bindings_.AddBinding(this, std::move(request));
 }
 
+void GpuService::RecordLogMessage(int severity,
+                                  size_t message_start,
+                                  const std::string& str) {
+  std::string header = str.substr(0, message_start);
+  std::string message = str.substr(message_start);
+  (*gpu_host_)->RecordLogMessage(severity, header, message);
+}
+
 void GpuService::CreateGpuMemoryBuffer(
     gfx::GpuMemoryBufferId id,
     const gfx::Size& size,