Experiment for disabling accelerated video decoding.

content/browser/gpu/gpu_data_manager_impl_private.cc

 // Copyright (c) 2013 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 "content/browser/gpu/gpu_data_manager_impl_private.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
@@ skipping 584 matching lines @@
   GpuDataManagerImpl::UnlockedSession session(owner_);
   observer_list_->Notify(FROM_HERE,
                          &GpuDataManagerObserver::OnVideoMemoryUsageStatsUpdate,
                          video_memory_usage_stats);
 }
 
 void GpuDataManagerImplPrivate::AppendRendererCommandLine(
     base::CommandLine* command_line) const {
   DCHECK(command_line);
 
-  if (IsFeatureBlacklisted(gpu::GPU_FEATURE_TYPE_ACCELERATED_VIDEO_DECODE) &&
-      !command_line->HasSwitch(switches::kDisableAcceleratedVideoDecode))
+  if (ShouldDisableAcceleratedVideoDecode(command_line))
     command_line->AppendSwitch(switches::kDisableAcceleratedVideoDecode);
 #if defined(ENABLE_WEBRTC)
   if (IsFeatureBlacklisted(gpu::GPU_FEATURE_TYPE_ACCELERATED_VIDEO_ENCODE) &&
       !command_line->HasSwitch(switches::kDisableWebRtcHWEncoding))
     command_line->AppendSwitch(switches::kDisableWebRtcHWEncoding);
 #endif
 
 #if defined(USE_AURA)
   if (!CanUseGpuBrowserCompositor())
     command_line->AppendSwitch(switches::kDisableGpuCompositing);
@@ skipping 34 matching lines @@
   if (!swiftshader_path.empty()) {
     command_line->AppendSwitchPath(switches::kSwiftShaderPath,
                                    swiftshader_path);
   }
 
   if (!gpu_driver_bugs_.empty()) {
     command_line->AppendSwitchASCII(switches::kGpuDriverBugWorkarounds,
                                     IntSetToString(gpu_driver_bugs_));
   }
 
-  if (IsFeatureBlacklisted(gpu::GPU_FEATURE_TYPE_ACCELERATED_VIDEO_DECODE) &&
-      !command_line->HasSwitch(switches::kDisableAcceleratedVideoDecode)) {
+  if (ShouldDisableAcceleratedVideoDecode(command_line)) {
     command_line->AppendSwitch(switches::kDisableAcceleratedVideoDecode);
   }
 #if defined(ENABLE_WEBRTC)
   if (IsFeatureBlacklisted(gpu::GPU_FEATURE_TYPE_ACCELERATED_VIDEO_ENCODE) &&
       !command_line->HasSwitch(switches::kDisableWebRtcHWEncoding)) {
     command_line->AppendSwitch(switches::kDisableWebRtcHWEncoding);
   }
 #endif
 
   // Pass GPU and driver information to GPU process. We try to avoid full GPU
@@ skipping 59 matching lines @@
        display_count_ > 1))
     prefs->gl_multisampling_enabled = false;
 
 #if defined(USE_AURA)
   if (!CanUseGpuBrowserCompositor()) {
     prefs->accelerated_2d_canvas_enabled = false;
     prefs->pepper_3d_enabled = false;
   }
 #endif
 
-  if (!IsFeatureBlacklisted(gpu::GPU_FEATURE_TYPE_ACCELERATED_VIDEO_DECODE) &&
-      !base::CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kDisableAcceleratedVideoDecode)) {
+  const base::CommandLine* command_line =
+      base::CommandLine::ForCurrentProcess();
+  if (!ShouldDisableAcceleratedVideoDecode(command_line) &&
+      !command_line->HasSwitch(switches::kDisableAcceleratedVideoDecode)) {
     prefs->pepper_accelerated_video_decode_enabled = true;
   }
 }
 
 void GpuDataManagerImplPrivate::DisableHardwareAcceleration() {
   card_blacklisted_ = true;
 
   for (int i = 0; i < gpu::NUMBER_OF_GPU_FEATURE_TYPES; ++i)
     blacklisted_features_.insert(i);
 
@@ skipping 117 matching lines @@
     return false;
   if (ShouldUseWarp())
     return true;
   if (ShouldUseSwiftShader())
     return false;
   if (IsFeatureBlacklisted(gpu::GPU_FEATURE_TYPE_GPU_COMPOSITING))
     return false;
   return true;
 }
 
+
+bool GpuDataManagerImplPrivate::ShouldDisableAcceleratedVideoDecode(
+    const base::CommandLine* command_line) const {
+  // Make sure that we initialize the experiment first to make sure that
+  // statistics are bucket correctly in all cases.

[Ken Russell (switch to Gerrit), 2015/05/04 21:10:05]

bucket -> bucketed

+  const std::string group_name = base::FieldTrialList::FindFullName(
+      "DisableAcceleratedVideoDecode");
+  if (command_line->HasSwitch(switches::kDisableAcceleratedVideoDecode)) {
+    // It was already disabled on the command line.
+    return false;
+  }
+  if (IsFeatureBlacklisted(gpu::GPU_FEATURE_TYPE_ACCELERATED_VIDEO_DECODE))
+    return true;
+  if (group_name == "Disabled")
+    return true;
+  return false;
+}
+
 void GpuDataManagerImplPrivate::GetDisabledExtensions(
     std::string* disabled_extensions) const {
   DCHECK(disabled_extensions);
 
   *disabled_extensions = disabled_extensions_;
 }
 
 void GpuDataManagerImplPrivate::BlockDomainFrom3DAPIs(
     const GURL& url, GpuDataManagerImpl::DomainGuilt guilt) {
   BlockDomainFrom3DAPIsAtTime(url, guilt, base::Time::Now());
@@ skipping 271 matching lines @@
   gpu_info_.context_info_state = gpu::kCollectInfoFatalFailure;
 #if defined(OS_WIN)
   gpu_info_.dx_diagnostics_info_state = gpu::kCollectInfoFatalFailure;
 #endif
   complete_gpu_info_already_requested_ = true;
   // Some observers might be waiting.
   NotifyGpuInfoUpdate();
 }
 
 }  // namespace content