Move simple png encoding for image_diff into tools/

android_webview/tools/third_party_files_whitelist.txt

 # 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.
 
 # This file records third-party licensing information for the purposes of the
 # Android WebView build. See webview_licenses.py for details.
 #
 # New third-party code should be added under a directory named 'third_party',
 # so additions to this file should be rare. See
 # http://www.chromium.org/developers/adding-3rd-party-libraries.
@@ skipping 129 matching lines @@
 # third-party code is taken from Mozilla, the license for which we already pick
 # up from third_party/npapi/.
 net/proxy/proxy_resolver_script.h
 # Copyright The Chromium Authors and Netscape Communications Corporation; BSD
 # and (MPL, GPL v2 or LGPL v2) licenses. Not used on Android.
 net/socket/ssl_client_socket_nss.cc
 # Copyright The Android Open Source Project; ASL v2 license.
 skia/config/SkUserConfig.h
 # Contains word 'copyright' in comments.
 tools/gen_keyboard_overlay_data/gen_keyboard_overlay_data.py
+# This third-party code is taken from Mozilla, but is copyright Google and has
+# been re-licensed under the Chromium license.
+tools/imagediff/image_diff_png.cc
 # Copyright Ero Carrera; BSD license. Tool only.
 tools/symsrc/pefile.py
 # Copyright The Chromium Authors, Sun Microsystems Inc, the V8 project authors;
 # BSD license. Tool only.
 tools/traceline/traceline/assembler.h
 # Copyright Google Inc; BSD license. Tool only.
 tools/traceline/traceline/sidestep/mini_disassembler.cc
 # Copyright The Chromium Authors, Apple Inc; BSD license. Not used on Android.
 ui/base/clipboard/clipboard_util_win.cc
 # Copyright The Chromium Authors, Apple Inc; BSD license. Not used on Android.
@@ skipping 26 matching lines @@
 # code is taken from WebKit, the license for which we already pick up from
 # webkit/.
 webkit/browser/appcache/manifest_parser.h
 # Copyright The Chromium Authors and Netscape Communications Corporation; BSD
 # and (MPL, GPL v2 or LGPL v2) licenses. This third-party code is taken from
 # Mozilla, the license for which we already pick up from third_party/npapi/.
 webkit/child/multipart_response_delegate.h
 # Copyright Tim Copperfield and Christian Dywan; LGPL license. Not used on
 # Android.
 webkit/common/cursors/webcursor_gtk_data.h
-# This third-party code is taken from Mozilla, but is copyright Google and has
-# been re-licensed under the Chromium license.
-webkit/support/webkit_support_gfx.cc
 # Copyright Apple, Inc, Graham Dennis and Eric Seidel; BSD license. Tool only
 webkit/support/mac/DumpRenderTreePasteboard.h
 # Copyright Apple, Inc, Graham Dennis and Eric Seidel; BSD license. Tool only
 webkit/support/mac/DumpRenderTreePasteboard.m