Add a JS API for detecting WebGL availability.

content/browser/gpu/gpu_process_host_ui_shim.cc

Index: content/browser/gpu/gpu_process_host_ui_shim.cc
===================================================================
--- content/browser/gpu/gpu_process_host_ui_shim.cc	(revision 112998)
+++ content/browser/gpu/gpu_process_host_ui_shim.cc	(working copy)
@@ -197,6 +197,8 @@
                         OnAcceleratedSurfaceBuffersSwapped)
     IPC_MESSAGE_HANDLER(GpuHostMsg_AcceleratedSurfacePostSubBuffer,
                         OnAcceleratedSurfacePostSubBuffer)
+    IPC_MESSAGE_HANDLER(GpuHostMsg_GraphicsInfoCollected,
+                        OnGraphicsInfoCollected)
 
 #if defined(TOOLKIT_USES_GTK) || defined(OS_WIN)
     IPC_MESSAGE_HANDLER(GpuHostMsg_ResizeView, OnResizeView)
@@ -229,6 +231,15 @@
   GpuDataManager::GetInstance()->AddLogMessage(dict);
 }
 
+void GpuProcessHostUIShim::OnGraphicsInfoCollected(
+    const content::GPUInfo& gpu_info) {
+  // OnGraphicsInfoCollected is sent back after the GPU process successfully
+  // initializes GL.
+  TRACE_EVENT0("test_gpu", "OnGraphicsInfoCollected");
+
+  GpuDataManager::GetInstance()->UpdateGpuInfo(gpu_info);
+}
+
 #if defined(TOOLKIT_USES_GTK) || defined(OS_WIN)
 
 void GpuProcessHostUIShim::OnResizeView(int32 renderer_id,