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..c1706af94e884b6eee158f2187e45c577744252e 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();
   };
 
+  // The helper method to simplify reporting of the status returned to UMA.
+  ArcVideoAccelerator::Result InitializeTask(
+      const Config& config,
+      ArcVideoAccelerator::Client* client);
+
   // Helper function to validate |port| and |index|.
   bool ValidatePortAndIndex(PortType port, uint32_t index) const;