The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3287e2051f82e1aa8c5daab8ed19e2a17a2b07e2

commit 3287e2051f82e1aa8c5daab8ed19e2a17a2b07e2
Author: dewittj <dewittj@chromium.org>
Date: Thu Apr 21 00:33:17 2016

Offline Pages: Use 'binary encoding' to create MHTML, instead of base64.

This results in a 33% space savings for images stored alongside MHTML.

This patch preserves the existing behavior for other creators of MHTML, the extension API and the 'save as' dialog (which is behind a flag).

BUG= 604413 

Review URL: https://codereview.chromium.org/1899803002

Cr-Commit-Position: refs/heads/master@{#388638}

[modify] https://crrev.com/3287e2051f82e1aa8c5daab8ed19e2a17a2b07e2/android_webview/native/aw_contents.cc
[modify] https://crrev.com/3287e2051f82e1aa8c5daab8ed19e2a17a2b07e2/chrome/browser/android/offline_pages/offline_page_mhtml_archiver.cc
[modify] https://crrev.com/3287e2051f82e1aa8c5daab8ed19e2a17a2b07e2/chrome/browser/extensions/api/page_capture/page_capture_api.cc
[modify] https://crrev.com/3287e2051f82e1aa8c5daab8ed19e2a17a2b07e2/content/browser/download/mhtml_generation_browsertest.cc
[modify] https://crrev.com/3287e2051f82e1aa8c5daab8ed19e2a17a2b07e2/content/browser/download/mhtml_generation_manager.cc
[modify] https://crrev.com/3287e2051f82e1aa8c5daab8ed19e2a17a2b07e2/content/browser/download/mhtml_generation_manager.h
[modify] https://crrev.com/3287e2051f82e1aa8c5daab8ed19e2a17a2b07e2/content/browser/download/save_package.cc
[modify] https://crrev.com/3287e2051f82e1aa8c5daab8ed19e2a17a2b07e2/content/browser/web_contents/web_contents_impl.cc
[modify] https://crrev.com/3287e2051f82e1aa8c5daab8ed19e2a17a2b07e2/content/browser/web_contents/web_contents_impl.h
[modify] https://crrev.com/3287e2051f82e1aa8c5daab8ed19e2a17a2b07e2/content/common/frame_messages.h
[modify] https://crrev.com/3287e2051f82e1aa8c5daab8ed19e2a17a2b07e2/content/public/browser/web_contents.h
[modify] https://crrev.com/3287e2051f82e1aa8c5daab8ed19e2a17a2b07e2/content/renderer/render_frame_impl.cc
[add] https://crrev.com/3287e2051f82e1aa8c5daab8ed19e2a17a2b07e2/content/test/data/blank.jpg
[add] https://crrev.com/3287e2051f82e1aa8c5daab8ed19e2a17a2b07e2/content/test/data/page_with_image.html