[devtools] Support different encodings for Page.CaptureScreenshot.

ui/gfx/image/image_util.cc

 // Copyright (c) 2012 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 <stdint.h>
 
 #include <algorithm>
 #include <memory>
@@ skipping 26 matching lines @@
 #if !defined(OS_IOS)
 Image ImageFrom1xJPEGEncodedData(const unsigned char* input,
                                  size_t input_size) {
   std::unique_ptr<SkBitmap> bitmap(gfx::JPEGCodec::Decode(input, input_size));
   if (bitmap.get())
     return Image::CreateFrom1xBitmap(*bitmap);
 
   return Image();
 }
 
-bool JPEG1xEncodedDataFromImage(const Image& image, int quality,
+// The MacOS implementation of this function is in image_utils_mac.mm.
+#if !defined(OS_MACOSX)
+bool JPEG1xEncodedDataFromImage(const Image& image,
+                                int quality,
                                 std::vector<unsigned char>* dst) {
+  return JPEG1xEncodedDataFromSkiaRepresentation(image, quality, dst);
+}
+#endif  // !defined(OS_MACOSX)
+
+bool JPEG1xEncodedDataFromSkiaRepresentation(const Image& image,
+                                             int quality,
+                                             std::vector<unsigned char>* dst) {
   const gfx::ImageSkiaRep& image_skia_rep =
       image.AsImageSkia().GetRepresentation(1.0f);
   if (image_skia_rep.scale() != 1.0f)
     return false;
 
   const SkBitmap& bitmap = image_skia_rep.sk_bitmap();
   SkAutoLockPixels bitmap_lock(bitmap);
 
   if (!bitmap.readyToDraw())
     return false;
@@ skipping 36 matching lines @@
   // Since we already know column *left is non-transparent, we can avoid
   // rechecking that column; hence the '>' here.
   for (x = bitmap.width() - 1; x > *left; --x) {
     if (ColumnHasVisiblePixels(bitmap, x))
       break;
   }
   *right = bitmap.width() - 1 - x;
 }
 
 }  // namespace gfx