Revert 162294 "This review merges the two existing page serializ..."

The patch breaks various Chromium browser_tests and content_browsertests.
Those tests must be updated to reflect the new behavior before relanding.

See, for example:
http://build.chromium.org/p/chromium.webkit/builders/Linux%20Tests/builds/32610

> This review merges the two existing page serializers, WebPageSerializerImpl and
> PageSerializer, into one, PageSerializer. In addition to this it moves all
> the old tests from WebPageNewSerializerTest and WebPageSerializerTest to the
> PageSerializerTest structure and splits out one test for MHTML into a new
> MHTMLTest file.
> 
> Saving as 'Webpage, Complete', 'Webpage, HTML Only' and as MHTML when the
> 'Save Page as MHTML' flag is enabled now uses the same code, and should thus
> have the same feature set. Meaning that both modes now should be a bit better.
> 
> Detailed list of changes:
> 
> - PageSerializerTest: Prepare for more DTD test
> - PageSerializerTest: Remove now unneccesary input image test
> - PageSerializerTest: Remove unused WebPageSerializer/Impl code
> - PageSerializerTest: Move data URI morph test
> - PageSerializerTest: Move data URI test
> - PageSerializerTest: Move namespace test
> - PageSerializerTest: Move SVG Image test
> - MHTMLTest: Move MHTML specific test to own test file
> - PageSerializerTest: Delete duplicate XML header test
> - PageSerializerTest: Move blank frame test
> - PageSerializerTest: Move CSS test
> - PageSerializerTest: Add frameset/frame test
> - PageSerializerTest: Move old iframe test
> - PageSerializerTest: Move old elements test
> - Use PageSerizer for saving web pages
> - PageSerializerTest: Test for rewriting links
> - PageSerializer: Add rewrite link accumulator
> - PageSerializer: Serialize images in iframes/frames src
> - PageSerializer: XHTML fix for meta tags
> - PageSerializer: Add presentation CSS
> - PageSerializer: Rename out parameter
> 
> BUG=
> R=abarth@chromium.org
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=162155
> 
> Review URL: https://codereview.chromium.org/68613003

TBR=tiger@opera.com,abarth@chromium.org

Review URL: https://codereview.chromium.org/65413005

git-svn-id: svn://svn.chromium.org/blink/trunk@162302 bbb929c8-8fbe-4397-9dbb-9b2b20218538