Updated OSX to blacklist multisampling when multiple monitors are connected

content/browser/gpu/gpu_data_manager_impl.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/browser/gpu/gpu_data_manager_impl.h"
 
 #if defined(OS_MACOSX)
 #include <ApplicationServices/ApplicationServices.h>
 #endif  // OS_MACOSX
 
@@ skipping 60 matching lines @@
       rt += ",";
     rt += base::IntToString(*it);
   }
   return rt;
 }
 
 #if defined(OS_MACOSX)
 void DisplayReconfigCallback(CGDirectDisplayID display,
                              CGDisplayChangeSummaryFlags flags,
                              void* gpu_data_manager) {
-  if (flags & kCGDisplayAddFlag) {
-    GpuDataManagerImpl* manager =
-        reinterpret_cast<GpuDataManagerImpl*>(gpu_data_manager);
-    DCHECK(manager);
+  if(flags == kCGDisplayBeginConfigurationFlag)
+    return; // This call contains no information about the display change
+
+  GpuDataManagerImpl* manager =
+      reinterpret_cast<GpuDataManagerImpl*>(gpu_data_manager);
+  DCHECK(manager);
+
+  uint32_t displayCount;
+  CGGetActiveDisplayList(0, NULL, &displayCount);
+
+  bool fireGpuSwitch = flags & kCGDisplayAddFlag;
+
+  if (displayCount != manager->display_count_) {
+    manager->display_count_ = displayCount;
+    fireGpuSwitch = true;
+  }
+
+  if (fireGpuSwitch)
     manager->HandleGpuSwitch();
-  }
 }
 #endif  // OS_MACOSX
 
 // Block all domains' use of 3D APIs for this many milliseconds if
 // approaching a threshold where system stability might be compromised.
 const int64 kBlockAllDomainsMs = 10000;
 const int kNumResetsWithinDuration = 1;
 
 // Enums for UMA histograms.
 enum BlockStatusHistogram {
@@ skipping 454 matching lines @@
   if (IsFeatureBlacklisted(GPU_FEATURE_TYPE_FLASH3D))
     prefs->flash_3d_enabled = false;
   if (IsFeatureBlacklisted(GPU_FEATURE_TYPE_FLASH_STAGE3D)) {
     prefs->flash_stage3d_enabled = false;
     prefs->flash_stage3d_baseline_enabled = false;
   }
   if (IsFeatureBlacklisted(GPU_FEATURE_TYPE_FLASH_STAGE3D_BASELINE))
     prefs->flash_stage3d_baseline_enabled = false;
   if (IsFeatureBlacklisted(GPU_FEATURE_TYPE_ACCELERATED_2D_CANVAS))
     prefs->accelerated_2d_canvas_enabled = false;
-  if (IsFeatureBlacklisted(GPU_FEATURE_TYPE_MULTISAMPLING))
+  if (IsFeatureBlacklisted(GPU_FEATURE_TYPE_MULTISAMPLING)
+      || display_count_ > 1)
     prefs->gl_multisampling_enabled = false;
   if (IsFeatureBlacklisted(GPU_FEATURE_TYPE_3D_CSS)) {
     prefs->accelerated_compositing_for_3d_transforms_enabled = false;
     prefs->accelerated_compositing_for_animation_enabled = false;
   }
   if (IsFeatureBlacklisted(GPU_FEATURE_TYPE_ACCELERATED_VIDEO))
     prefs->accelerated_compositing_for_video_enabled = false;
 
   // Accelerated video and animation are slower than regular when using
   // SwiftShader. 3D CSS may also be too slow to be worthwhile.
@@ skipping 133 matching lines @@
     DisableHardwareAcceleration();
   if (command_line->HasSwitch(switches::kGpuSwitching)) {
     std::string option_string = command_line->GetSwitchValueASCII(
         switches::kGpuSwitching);
     GpuSwitchingOption option = StringToGpuSwitchingOption(option_string);
     if (option != GPU_SWITCHING_OPTION_UNKNOWN)
       gpu_switching_ = option;
   }
 
 #if defined(OS_MACOSX)
+  CGGetActiveDisplayList (0, NULL, &display_count_);
   CGDisplayRegisterReconfigurationCallback(DisplayReconfigCallback, this);
 #endif  // OS_MACOSX
 }
 
 GpuDataManagerImpl::~GpuDataManagerImpl() {
 #if defined(OS_MACOSX)
   CGDisplayRemoveReconfigurationCallback(DisplayReconfigCallback, this);
 #endif
 }
 
@@ skipping 187 matching lines @@
 
 void GpuDataManagerImpl::Notify3DAPIBlocked(const GURL& url,
                                             int render_process_id,
                                             int render_view_id,
                                             ThreeDAPIType requester) {
   observer_list_->Notify(&GpuDataManagerObserver::DidBlock3DAPIs,
                          url, render_process_id, render_view_id, requester);
 }
 
 }  // namespace content