Remove static thread pointers from CC

cc/resource_provider.h

Index: cc/resource_provider.h
diff --git a/cc/resource_provider.h b/cc/resource_provider.h
index 6262d316c1023c745ba097aee76f0645292cb501..59dc65a5f10cb90fdc788785199b0477fe556cef 100644
--- a/cc/resource_provider.h
+++ b/cc/resource_provider.h
@@ -8,6 +8,7 @@
 #include "base/basictypes.h"
 #include "base/hash_tables.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/threading/thread_checker.h"
 #include "cc/cc_export.h"
 #include "cc/graphics_context.h"
 #include "cc/texture_copier.h"
@@ -31,8 +32,8 @@ namespace cc {
 
 class TextureUploader;
 
-// Thread-safety notes: this class is not thread-safe and can only be called
-// from the thread it was created on (in practice, the compositor thread).
+// This class is not thread-safe and can only be called from the thread it was
+// created on (in practice, the impl thread).
 class CC_EXPORT ResourceProvider {
 public:
     typedef unsigned ResourceId;
@@ -277,6 +278,8 @@ private:
     scoped_ptr<AcceleratedTextureCopier> m_textureCopier;
     int m_maxTextureSize;
 
+    base::ThreadChecker m_threadChecker;
+
     DISALLOW_COPY_AND_ASSIGN(ResourceProvider);
 };