Implement blacklist's force GPU capability in dual GPU machines.

content/browser/gpu/gpu_data_manager_impl.cc

Index: content/browser/gpu/gpu_data_manager_impl.cc
===================================================================
--- content/browser/gpu/gpu_data_manager_impl.cc	(revision 156326)
+++ content/browser/gpu/gpu_data_manager_impl.cc	(working copy)
@@ -48,7 +48,7 @@
     : complete_gpu_info_already_requested_(false),
       gpu_feature_type_(content::GPU_FEATURE_TYPE_UNKNOWN),
       preliminary_gpu_feature_type_(content::GPU_FEATURE_TYPE_UNKNOWN),
-      gpu_switching_(content::GPU_SWITCHING_AUTOMATIC),
+      gpu_switching_(content::GPU_SWITCHING_OPTION_AUTOMATIC),
       observer_list_(new GpuDataManagerObserverList),
       software_rendering_(false),
       card_blacklisted_(false),
@@ -299,6 +299,18 @@
   } else if (!use_gl.empty()) {
     command_line->AppendSwitchASCII(switches::kUseGL, use_gl);
   }
+  switch (gpu_switching_) {
+    case content::GPU_SWITCHING_OPTION_FORCE_DISCRETE:
+      command_line->AppendSwitchASCII(switches::kGpuSwitching,
+          kGpuSwitchingOptionNameForceDiscrete);
+      break;
+    case content::GPU_SWITCHING_OPTION_FORCE_INTEGRATED:
+      command_line->AppendSwitchASCII(switches::kGpuSwitching,
+          kGpuSwitchingOptionNameForceIntegrated);
+      break;
+    default:
+      break;
+  }
 
   if (!swiftshader_path.empty())
     command_line->AppendSwitchPath(switches::kSwiftShaderPath,