gpu: Simplify the error handling during gpu memory buffer allocation.

content/browser/gpu/gpu_process_host.h

Index: content/browser/gpu/gpu_process_host.h
diff --git a/content/browser/gpu/gpu_process_host.h b/content/browser/gpu/gpu_process_host.h
index cb0ca81c7bb7ac886c7d1b8241d930e577587b87..7b25454b7e93a7f81bccf3933fd9914ca903f770 100644
--- a/content/browser/gpu/gpu_process_host.h
+++ b/content/browser/gpu/gpu_process_host.h
@@ -79,8 +79,13 @@ class GpuProcessHost : public BrowserChildProcessHostDelegate,
                           const gpu::GPUInfo&,
                           EstablishChannelStatus status)>;
 
-  typedef base::Callback<void(const gfx::GpuMemoryBufferHandle& handle)>
-      CreateGpuMemoryBufferCallback;
+  enum class BufferCreationStatus {
+    GPU_HOST_INVALID,
+    SUCCESS,
+  };
+  using CreateGpuMemoryBufferCallback =
+      base::Callback<void(const gfx::GpuMemoryBufferHandle& handle,
+                          BufferCreationStatus status)>;
 
   static bool gpu_enabled() { return gpu_enabled_; }
   static int gpu_crash_count() { return gpu_crash_count_; }