Remove parts of //cc we aren't using

cc/debug/picture_debug_util.h

Index: cc/debug/picture_debug_util.h
diff --git a/cc/debug/picture_debug_util.h b/cc/debug/picture_debug_util.h
deleted file mode 100644
index 1719ea27632894b51a6ac0627fa4bd66e4487ff6..0000000000000000000000000000000000000000
--- a/cc/debug/picture_debug_util.h
+++ /dev/null
@@ -1,21 +0,0 @@
-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef CC_DEBUG_PICTURE_DEBUG_UTIL_H_
-#define CC_DEBUG_PICTURE_DEBUG_UTIL_H_
-
-#include <string>
-
-class SkPicture;
-
-namespace cc {
-
-class PictureDebugUtil {
- public:
-  static void SerializeAsBase64(const SkPicture* picture, std::string* output);
-};
-
-}  // namespace cc
-
-#endif  // CC_DEBUG_PICTURE_DEBUG_UTIL_H_