Revert of [devtools] Support different encodings for Page.CaptureScreenshot.

ui/gfx/image/image_util_mac.mm

-// Copyright (c) 2017 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"
-
-#import <Cocoa/Cocoa.h>
-
-#include "base/mac/scoped_nsobject.h"
-#include "ui/gfx/image/image.h"
-
-namespace gfx {
-
-bool JPEG1xEncodedDataFromImage(const Image& image,
-                                int quality,
-                                std::vector<unsigned char>* dst) {
-  if (!image.HasRepresentation(gfx::Image::kImageRepCocoa))
-    return JPEG1xEncodedDataFromSkiaRepresentation(image, quality, dst);
-
-  NSImage* nsImage = image.ToNSImage();
-
-  CGImageRef cgImage =
-      [nsImage CGImageForProposedRect:nil context:nil hints:nil];
-  base::scoped_nsobject<NSBitmapImageRep> rep(
-      [[NSBitmapImageRep alloc] initWithCGImage:cgImage]);
-
-  float compressionFactor = quality / 100.0;
-  NSDictionary* options = @{ NSImageCompressionFactor : @(compressionFactor)};
-  NSData* data =
-      [rep representationUsingType:NSJPEGFileType properties:options];
-
-  if ([data length] == 0)
-    return false;
-
-  dst->resize([data length]);
-  [data getBytes:&dst->at(0) length:[data length]];
-  return true;
-}
-
-}  // end namespace gfx