Disable threaded compositing when texture sharing is blacklisted

content/browser/gpu/compositor_util.cc

 // Copyright (c) 2012 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/public/browser/compositor_util.h"
 
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
 #include "content/public/browser/gpu_data_manager.h"
 #include "content/public/common/content_constants.h"
@@ skipping 29 matching lines @@
 
 bool IsThreadedCompositingEnabled() {
 #if defined(OS_WIN) && defined(USE_AURA)
   // We always want compositing on Aura Windows.
   return true;
 #endif
 
   if (!CanDoAcceleratedCompositing())
     return false;
 
+  const GpuDataManager* gpu_data_manager = GpuDataManager::GetInstance();
+  GpuFeatureType blacklisted_features =
+      gpu_data_manager->GetBlacklistedFeatures();
+  // Disallow threaded compositing when texture sharing is blacklisted since
+  // this triggers renderer-side readbacks for the thumbnailer / extensions.
+  // http://crbug.com/158747
+  if (blacklisted_features & GPU_FEATURE_TYPE_TEXTURE_SHARING)
+    return false;
+
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
 
   // Command line switches take precedence over field trials.
   if (command_line.HasSwitch(switches::kDisableForceCompositingMode) ||
       command_line.HasSwitch(switches::kDisableThreadedCompositing))
     return false;
 
   if (command_line.HasSwitch(switches::kEnableThreadedCompositing))
     return true;
 
@@ skipping 26 matching lines @@
 
   // Force compositing is enabled in both the force compositing
   // and threaded compositing mode field trials.
   return trial &&
         (trial->group_name() ==
             kGpuCompositingFieldTrialForceCompositingEnabledName ||
          trial->group_name() == kGpuCompositingFieldTrialThreadEnabledName);
 }
 
 }  // namespace content