cc: Fix resource provider fences and add DCHECKs.

content/renderer/gpu/compositor_output_surface.cc

Index: content/renderer/gpu/compositor_output_surface.cc
diff --git a/content/renderer/gpu/compositor_output_surface.cc b/content/renderer/gpu/compositor_output_surface.cc
index 2b18c357317fa617559009923ae85cdb946e9e05..da7c3c129a201bffe6d9a245589b39b2b036c74e 100644
--- a/content/renderer/gpu/compositor_output_surface.cc
+++ b/content/renderer/gpu/compositor_output_surface.cc
@@ -149,10 +149,10 @@ namespace {
 
 void CompositorOutputSurface::UpdateSmoothnessTakesPriority(
     bool prefers_smoothness) {
-#if ENABLE_DCHECK
+#ifndef NDEBUG
   // If we use different compositor threads, we need to
   // use an atomic int to track prefer smoothness count.
-  static int g_last_thread = base::PlatformThread::CurrentId();
+  base::PlatformThreadId g_last_thread = base::PlatformThread::CurrentId();

[joth, 2013/04/05 05:30:32]

removing the static here makes the dcheck below pointless? (And, g_ prefix does
not make sense as it's a plain local var)

can probably write this as:
  static NonThreadSafe g_nts;
  DCHECK(g_nts.CalledOnValidThread());
(no need for ifdef)

   DCHECK_EQ(g_last_thread, base::PlatformThread::CurrentId());
 #endif
   if (prefers_smoothness_ == prefers_smoothness)