[ntp4] Use highest quality jpeg compression for thumbnail images.

ui/gfx/image/image_util.cc

 // Copyright (c) 2011 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 "ui/gfx/image/image_util.h"
 
 #include "base/memory/scoped_ptr.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/gfx/codec/jpeg_codec.h"
 #include "ui/gfx/codec/png_codec.h"
 #include "ui/gfx/image/image.h"
 
 namespace gfx {
 
 Image* ImageFromPNGEncodedData(const unsigned char* input, size_t input_size) {
   scoped_ptr<SkBitmap> favicon_bitmap(new SkBitmap());
   if (gfx::PNGCodec::Decode(input, input_size, favicon_bitmap.get()))
     return new Image(favicon_bitmap.release());
 
   return NULL;
 }
 
 bool PNGEncodedDataFromImage(const Image& image,
                              std::vector<unsigned char>* dst) {
   const SkBitmap& bitmap = image;
   return gfx::PNGCodec::EncodeBGRASkBitmap(bitmap, false, dst);
 }
 
-bool JPEGEncodedDataFromImage(const Image& image,
+bool JPEGEncodedDataFromImage(const Image& image, int quality,
                               std::vector<unsigned char>* dst) {
   const SkBitmap& bitmap = image;
   SkAutoLockPixels bitmap_lock(bitmap);
 
   if (!bitmap.readyToDraw())
     return false;
 
-  // Use 90 quality (out of 100) which is pretty high, because
-  // we're very sensitive to artifacts for these small sized,
-  // highly detailed images.
   return gfx::JPEGCodec::Encode(
           reinterpret_cast<unsigned char*>(bitmap.getAddr32(0, 0)),
           gfx::JPEGCodec::FORMAT_BGRA, bitmap.width(),
           bitmap.height(),
-          static_cast<int>(bitmap.rowBytes()), 90,
+          static_cast<int>(bitmap.rowBytes()), quality,
           dst);
 }
 
 }