Add UMA to track software fallback in VTVideoDecodeAccelerator.

content/common/gpu/media/vt_video_decode_accelerator.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <algorithm>
 
 #include <CoreVideo/CoreVideo.h>
 #include <OpenGL/CGLIOSurface.h>
 #include <OpenGL/gl.h>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/mac/mac_logging.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/sys_byteorder.h"
 #include "base/thread_task_runner_handle.h"
 #include "content/common/gpu/media/vt_video_decode_accelerator.h"
 #include "content/public/common/content_switches.h"
 #include "media/base/limits.h"
 #include "ui/gl/scoped_binders.h"
 
 using content_common_gpu_media::kModuleVt;
 using content_common_gpu_media::InitializeStubs;
 using content_common_gpu_media::IsVtInitialized;
@@ skipping 286 matching lines @@
 
   CFDictionarySetValue(
       decoder_config,
       // kVTVideoDecoderSpecification_EnableHardwareAcceleratedVideoDecoder
       CFSTR("EnableHardwareAcceleratedVideoDecoder"),
       kCFBooleanTrue);
 
   base::ScopedCFTypeRef<CFMutableDictionaryRef> image_config(
       BuildImageConfig(coded_dimensions));
 
-  // TODO(sandersd): Does the old session need to be flushed first?
+  if (!FinishDelayedFrames())

[Pawel Osciak, 2014/12/02 01:21:51]

This is I think not related to this CL?

[sandersd (OOO until July 31), 2014/12/02 01:25:31]

Done.

+    return false;
   session_.reset();
   status = VTDecompressionSessionCreate(
       kCFAllocatorDefault,
       format_,              // video_format_description
       decoder_config,       // video_decoder_specification
       image_config,         // destination_image_buffer_attributes
       &callback_,           // output_callback
       session_.InitializeInto());
   if (status) {
     NOTIFY_STATUS("VTDecompressionSessionCreate()", status);
     return false;
   }
 
+  // Report whether hardware decode is being used.
+  base::ScopedCFTypeRef<CFBooleanRef> using_hardware;
+  if (VTSessionCopyProperty(
+        session_,
+        // kVTDecompressionPropertyKey_UsingHardwareAcceleratedVideoDecoder
+        CFSTR("UsingHardwareAcceleratedVideoDecoder"),
+        kCFAllocatorDefault,
+        using_hardware.InitializeInto()) == 0) {
+    UMA_HISTOGRAM_BOOLEAN("Media.VTVDA.UsingHardware",
+                          CFBooleanGetValue(using_hardware));
+  }
+
   return true;
 }
 
 void VTVideoDecodeAccelerator::DecodeTask(
     const media::BitstreamBuffer& bitstream,
     Frame* frame) {
   DCHECK(decoder_thread_.message_loop_proxy()->BelongsToCurrentThread());
 
   // Map the bitstream buffer.
   base::SharedMemory memory(bitstream.handle(), true);
@@ skipping 540 matching lines @@
   assigned_bitstream_ids_.clear();
   state_ = STATE_DESTROYING;
   QueueFlush(TASK_DESTROY);
 }
 
 bool VTVideoDecodeAccelerator::CanDecodeOnIOThread() {
   return false;
 }
 
 }  // namespace content