Wire the AMD switchable videcard detection

content/gpu/gpu_info_collector_win.cc

Index: content/gpu/gpu_info_collector_win.cc
===================================================================
--- content/gpu/gpu_info_collector_win.cc	(revision 147262)
+++ content/gpu/gpu_info_collector_win.cc	(working copy)
@@ -153,6 +153,16 @@
 
 namespace gpu_info_collector {
 
+#if !defined(OFFICIAL_BUILD)
+AMDVideoCardType GetAMDVideocardType() {
+  return UNKNOWN;
+}
+#else
+// This function has a real implementation for official builds that can
+// be found in src/third_party/amd.
+AMDVideoCardType GetAMDVideocardType();
+#endif
+
 bool CollectGraphicsInfo(content::GPUInfo* gpu_info) {
   TRACE_EVENT0("gpu", "CollectGraphicsInfo");
 
@@ -344,12 +354,13 @@
             reinterpret_cast<LPBYTE>(value), &dwcb_data);
         if (result == ERROR_SUCCESS) {
           driver_vendor = WideToASCII(std::wstring(value));
-          // If it's an Intel GPU with a driver provided by AMD then it's
-          // probably AMD's Dynamic Switchable Graphics.
-          // TODO: detect only AMD switchable
-          gpu_info->amd_switchable =
-              driver_vendor == "Advanced Micro Devices, Inc." ||
-              driver_vendor == "ATI Technologies Inc.";
+          if (driver_vendor == "Advanced Micro Devices, Inc." ||
+              driver_vendor == "ATI Technologies Inc.") {
+            // We are conservative and assume that in the absense of a clear
+            // signal the videocard is assumed to be switchable.
+            AMDVideoCardType amd_card_type = GetAMDVideocardType();
+            gpu_info->amd_switchable = (amd_card_type != STANDALONE);
+          }
         }
 
         gpu_info->driver_vendor = driver_vendor;