gpu: ContextProvider::BindToCurrentThread() should be called one time.

content/renderer/render_thread_impl.cc

Index: content/renderer/render_thread_impl.cc
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index 3975856b9b0a14cfd62120fd9ddbb8ec296a849c..930d476afda8fa9d79d03ba4ba7c59b357e7f8dc 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -1177,10 +1177,10 @@ RenderThreadImpl::SharedMainThreadContextProvider() {
       shared_main_thread_contexts_ = ContextProviderCommandBuffer::Create(
           CreateOffscreenContext3d(), "Offscreen-MainThread");
     }
+    if (shared_main_thread_contexts_ &&

[danakj, 2014/08/15 16:23:54]

it's never null here right?

[dshwang, 2014/08/15 16:50:16]

No, above factory method can return NULL.

[danakj, 2014/08/15 16:52:35]

But ContextProviderCommandBuffer::Create won't if the context it's given is not
null. And CreateOffscreenContext3d can't return NULL. I think. Do you agree?

[dshwang, 2014/08/15 17:28:39]

IMO CreateOffscreenContext3d() can return NULL. For example, it
s called during gpu process down.
https://code.google.com/p/chromium/codesearch#chromium/src/content/renderer/r...

[danakj, 2014/08/15 17:30:43]

Ah okay ya, I had to go one deeper. LGTM

+        !shared_main_thread_contexts_->BindToCurrentThread())
+      shared_main_thread_contexts_ = NULL;
   }
-  if (shared_main_thread_contexts_ &&
-      !shared_main_thread_contexts_->BindToCurrentThread())
-    shared_main_thread_contexts_ = NULL;
   return shared_main_thread_contexts_;
 }