Revert r150228 "Add support for PNG representation in gfx::Image"

ui/gfx/image/image_mac.mm

Index: ui/gfx/image/image_mac.mm
diff --git a/ui/gfx/image/image_mac.mm b/ui/gfx/image/image_mac.mm
deleted file mode 100644
index ce02b5e160d979f6251fa237732311c4d7767b48..0000000000000000000000000000000000000000
--- a/ui/gfx/image/image_mac.mm
+++ /dev/null
@@ -1,47 +0,0 @@
-// 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.h"
-
-#import <AppKit/AppKit.h>
-
-#include "base/logging.h"
-#include "base/memory/scoped_nsobject.h"
-
-namespace gfx {
-namespace internal {
-
-void PNGFromNSImage(NSImage* nsimage, std::vector<unsigned char>* png) {
-  CGImageRef cg_image = [nsimage CGImageForProposedRect:NULL
-                                                context:nil
-                                                  hints:nil];
-  scoped_nsobject<NSBitmapImageRep> ns_bitmap(
-      [[NSBitmapImageRep alloc] initWithCGImage:cg_image]);
-  NSData* ns_data = [ns_bitmap representationUsingType:NSPNGFileType
-                                            properties:nil];
-  const unsigned char* bytes =
-      static_cast<const unsigned char*>([ns_data bytes]);
-  png->assign(bytes, bytes + [ns_data length]);
-}
-
-NSImage* NSImageFromPNG(const std::vector<unsigned char>& png) {
-  scoped_nsobject<NSData> ns_data(
-      [[NSData alloc] initWithBytes:&png.front() length:png.size()]);
-  scoped_nsobject<NSImage> image([[NSImage alloc] initWithData:ns_data]);
-  if (!image) {
-    LOG(WARNING) << "Unable to decode PNG.";
-    // Return a 16x16 red image to visually show error.
-    NSRect rect = NSMakeRect(0, 0, 16, 16);
-    image.reset([[NSImage alloc] initWithSize:rect.size]);
-    [image lockFocus];
-    [[NSColor colorWithDeviceRed:1.0 green:0.0 blue:0.0 alpha:1.0] set];
-    NSRectFill(rect);
-    [image unlockFocus];
-  }
-  return image.release();
-}
-
-} // namespace internal
-} // namespace gfx
-