gpu: Fix some context lost marking glitches+leaks and add UMA stats

content/renderer/render_widget.cc

Index: content/renderer/render_widget.cc
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index 1aab8b42fc06fd0573f5d5ab6d503e42ea25e637..25dfb6444c5a15ba4d2669a6602c2c0312c75fa5 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -1011,14 +1011,14 @@ scoped_ptr<cc::OutputSurface> RenderWidget::CreateOutputSurface(bool fallback) {
   scoped_refptr<ContextProviderCommandBuffer> worker_context_provider;
   if (!use_software) {
     context_provider = ContextProviderCommandBuffer::Create(
-        CreateGraphicsContext3D(), "RenderCompositor");
+        CreateGraphicsContext3D(), RENDER_COMPOSITOR_CONTEXT);
     if (!context_provider.get()) {
       // Cause the compositor to wait and try again.
       return scoped_ptr<cc::OutputSurface>();
     }
 
     worker_context_provider = ContextProviderCommandBuffer::Create(
-        CreateGraphicsContext3D(), "RenderWorker");
+        CreateGraphicsContext3D(), RENDER_WORKER_CONTEXT);
     if (!worker_context_provider.get()) {
       // Cause the compositor to wait and try again.
       return scoped_ptr<cc::OutputSurface>();