Revert of Make SkPicture/SkImageGenerator default to SkCodec

tools/LazyDecodeBitmap.h

+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef LazyDecodeBitmap_DEFINED
+#define LazyDecodeBitmap_DEFINED
+
+#include "SkTypes.h"
+
+class SkBitmap;
+
+namespace sk_tools {
+
+/**
+ * Decode the image with DecodeMemoryToTarget but defer the process until it is needed.
+ */
+bool LazyDecodeBitmap(const void* buffer, size_t size, SkBitmap* bitmap);
+
+}
+
+#endif  // LazyDecodeBitmap_DEFINED