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 3b66f9b5f44e53cb635b9734fca2a1d485732df0..95c2b1b567777a110e936a1feba7f280a1fefeae 100644
--- a/cc/resource_provider.h
+++ b/cc/resource_provider.h
@@ -9,6 +9,7 @@
 #include "base/basictypes.h"
 #include "base/hash_tables.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/threading/thread_checker.h"
 #include "cc/graphics_context.h"
 #include "cc/texture_copier.h"
 #include "third_party/khronos/GLES2/gl2.h"
@@ -28,8 +29,8 @@ class LayerTextureSubImage;
 class TextureCopier;
 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 ResourceProvider {
 public:
     typedef unsigned ResourceId;
@@ -274,6 +275,8 @@ private:
     scoped_ptr<AcceleratedTextureCopier> m_textureCopier;
     int m_maxTextureSize;
 
+    base::ThreadChecker m_threadChecker;
+
     DISALLOW_COPY_AND_ASSIGN(ResourceProvider);
 };