Revert of extract some common code from PictureRenderer

gm/gm_expectations.h

Index: gm/gm_expectations.h
diff --git a/gm/gm_expectations.h b/gm/gm_expectations.h
index 70921273380ab8b13cf609ff739cdb466fbd322b..d454732dad3997b1be09faaa846857b18ba3e682 100644
--- a/gm/gm_expectations.h
+++ b/gm/gm_expectations.h
@@ -3,8 +3,6 @@
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
- *
- * TODO(epoger): Combine this with tools/image_expectations.h, or eliminate one of the two.
  */
 #ifndef gm_expectations_DEFINED
 #define gm_expectations_DEFINED
@@ -218,6 +216,47 @@
     private:
 
         /**
+         * Read as many bytes as possible (up to maxBytes) from the stream into
+         * an SkData object.
+         *
+         * If the returned SkData contains fewer than maxBytes, then EOF has been
+         * reached and no more data would be available from subsequent calls.
+         * (If EOF has already been reached, then this call will return an empty
+         * SkData object immediately.)
+         *
+         * If there are fewer than maxBytes bytes available to read from the
+         * stream, but the stream has not been closed yet, this call will block
+         * until there are enough bytes to read or the stream has been closed.
+         *
+         * It is up to the caller to call unref() on the returned SkData object
+         * once the data is no longer needed, so that the underlying buffer will
+         * be freed.  For example:
+         *
+         * {
+         *   size_t maxBytes = 256;
+         *   SkAutoDataUnref dataRef(readIntoSkData(stream, maxBytes));
+         *   if (NULL != dataRef.get()) {
+         *     size_t bytesActuallyRead = dataRef.get()->size();
+         *     // use the data...
+         *   }
+         * }
+         * // underlying buffer has been freed, thanks to auto unref
+         *
+         */
+        // TODO(epoger): Move this, into SkStream.[cpp|h] as attempted in
+        // https://codereview.appspot.com/7300071 ?
+        // And maybe ReadFileIntoSkData() also?
+        static SkData* ReadIntoSkData(SkStream &stream, size_t maxBytes);
+
+        /**
+         * Wrapper around ReadIntoSkData for files: reads the entire file into
+         * an SkData object.
+         */
+        static SkData* ReadFileIntoSkData(SkFILEStream &stream) {
+            return ReadIntoSkData(stream, stream.getLength());
+        }
+
+        /**
          * Read the file contents from jsonPath and parse them into jsonRoot.
          *
          * Returns true if successful.