cc: Remove low quality mode and cleanup tile versions.

cc/resources/raster_mode.cc

-// Copyright 2013 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.
-
-#include "cc/resources/raster_mode.h"
-
-#include "base/logging.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/values.h"
-
-namespace cc {
-
-std::string RasterModeToString(RasterMode raster_mode) {
-  switch (raster_mode) {
-    case HIGH_QUALITY_RASTER_MODE:
-      return "HIGH_QUALITY_RASTER_MODE";
-    case LOW_QUALITY_RASTER_MODE:
-      return "LOW_QUALITY_RASTER_MODE";
-    default:
-      NOTREACHED() << "Unrecognized RasterMode value " << raster_mode;
-      return "<unknown RasterMode value>";
-  }
-}
-
-}  // namespace cc