adds WARP support to Chromium, for Metro mode only, on Windows 8

gpu/config/gpu_info_collector_win.cc

Index: gpu/config/gpu_info_collector_win.cc
diff --git a/gpu/config/gpu_info_collector_win.cc b/gpu/config/gpu_info_collector_win.cc
index 8968d41a2a7f3c9bb1148f670f2cce847af592ce..8e39683b662970df1e52e49b400e614e063877ed 100644
--- a/gpu/config/gpu_info_collector_win.cc
+++ b/gpu/config/gpu_info_collector_win.cc
@@ -632,6 +632,18 @@ CollectInfoResult CollectBasicGraphicsInfo(GPUInfo* gpu_info) {
   return kCollectInfoSuccess;
 }
 
+namespace {
+  static bool g_should_fallback_to_warp = false;
+}
+
+bool ShouldFallbackToWarp() {
+  return g_should_fallback_to_warp;
+}
+
+void SetShouldFallbackToWarp(bool enable) {
+  g_should_fallback_to_warp = enable;
+}
+
 CollectInfoResult CollectDriverInfoGL(GPUInfo* gpu_info) {
   TRACE_EVENT0("gpu", "CollectDriverInfoGL");