Add Media.ArcGpuVideoDecodeAccelerator.InitializeResult to histograms

chrome/gpu/arc_gpu_video_decode_accelerator.h

Index: chrome/gpu/arc_gpu_video_decode_accelerator.h
diff --git a/chrome/gpu/arc_gpu_video_decode_accelerator.h b/chrome/gpu/arc_gpu_video_decode_accelerator.h
index 2747c55a13462fe5628902a8becc0930d54f3f7d..ccf3b268041bbcb4b27300bfc2eb581d8b357264 100644
--- a/chrome/gpu/arc_gpu_video_decode_accelerator.h
+++ b/chrome/gpu/arc_gpu_video_decode_accelerator.h
@@ -105,6 +105,11 @@ class ArcGpuVideoDecodeAccelerator
     ~OutputBufferInfo();
   };
 
+  // Intialization process.

[Pawel Osciak, 2016/11/21 09:02:37]

Perhaps we would be able to have a more descriptive sentence, e.g. "a helper
method to simplify reporting of the status returned to UMA."

[johnylin1, 2016/11/21 15:39:58]

Done.

+  ArcVideoAccelerator::Result InitializeTask(
+      const Config& config,
+      ArcVideoAccelerator::Client* client);
+
   // Helper function to validate |port| and |index|.
   bool ValidatePortAndIndex(PortType port, uint32_t index) const;