[M44 Merge] Refine dual-GPU detection on Mac OS X.

ui/gl/gpu_switching_manager.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 "ui/gl/gpu_switching_manager.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "ui/gl/gl_switches.h"
 
@@ skipping 14 matching lines @@
 // static
 GpuSwitchingManager* GpuSwitchingManager::GetInstance() {
   return Singleton<GpuSwitchingManager>::get();
 }
 
 GpuSwitchingManager::GpuSwitchingManager()
     : gpu_switching_option_(gfx::PreferIntegratedGpu),
       gpu_switching_option_set_(false),
       supports_dual_gpus_(false),
       supports_dual_gpus_set_(false),
-      gpu_count_(0),
       platform_specific_(new PlatformSpecific) {
 #if defined(OS_MACOSX)
   platform_specific_->discrete_pixel_format = nullptr;
 #endif  // OS_MACOSX
 }
 
 GpuSwitchingManager::~GpuSwitchingManager() {
 #if defined(OS_MACOSX)
   if (platform_specific_->discrete_pixel_format)
     CGLReleasePixelFormat(platform_specific_->discrete_pixel_format);
@@ skipping 38 matching lines @@
         flag = true;
       } else if (flag_string == "false") {
         flag = false;
       } else {
         NOTIMPLEMENTED();
       }
     } else {
       // Browser process.
       // We only compute this flag in the browser process.
 #if defined(OS_MACOSX)
-      flag = (gpu_count_ == 2);
+      flag = (vendor_ids_.size() == 2);
       if (flag && command_line.HasSwitch(switches::kUseGL) &&
           command_line.GetSwitchValueASCII(switches::kUseGL) !=
             gfx::kGLImplementationDesktopName)
         flag = false;
 
       if (flag && !base::mac::IsOSLionOrLater())
         flag = false;
+
+      if (flag) {
+        // Only advertise that we have two GPUs to the rest of
+        // Chrome's code if we find an Intel GPU and some other
+        // vendor's GPU. Otherwise we don't understand the
+        // configuration and don't deal well with it (an example being
+        // the dual AMD GPUs in recent Mac Pros).
+        const uint32 intel = 0x8086;
+        flag = ((vendor_ids_[0] == intel && vendor_ids_[1] != intel) ||
+                (vendor_ids_[0] != intel && vendor_ids_[1] == intel));
+      }
 #endif  // OS_MACOSX
     }
     supports_dual_gpus_ = flag;
     supports_dual_gpus_set_ = true;
   }
   return supports_dual_gpus_;
 }
 
-void GpuSwitchingManager::SetGpuCount(size_t gpu_count) {
-  gpu_count_ = gpu_count;
+void GpuSwitchingManager::SetGpuVendorIds(
+    const std::vector<uint32>& vendor_ids) {
+  vendor_ids_ = vendor_ids;
 }
 
 void GpuSwitchingManager::AddObserver(GpuSwitchingObserver* observer) {
   observer_list_.AddObserver(observer);
 }
 
 void GpuSwitchingManager::RemoveObserver(GpuSwitchingObserver* observer) {
   observer_list_.RemoveObserver(observer);
 }
 
@@ skipping 14 matching lines @@
     return;
   CGLPixelFormatAttribute attribs[1];
   attribs[0] = static_cast<CGLPixelFormatAttribute>(0);
   GLint num_pixel_formats = 0;
   CGLChoosePixelFormat(attribs, &platform_specific_->discrete_pixel_format,
                        &num_pixel_formats);
 }
 #endif  // OS_MACOSX
 
 }  // namespace ui