Make LayerDebugInfo's JSON writing robust

Rather than rolling our own JSON, let's use a tried-and-true writer.

TEST=LayerWithNullDelegateTest.EscapedDebugNames
R=danakj@chromium.org, enne@chromium.org
BUG=336138

Review URL: https://codereview.chromium.org/143873008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246380 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246380
[NaCl SDK Docs] Move doc images from "_images" to "images" for Chromesite.

Sphinx will copy the images into the build directory, but it renames the
directory to "_images", which breaks all the links.

This CL modifies the doc Makefile to move the _images directory to the
images directory after running sphinx.

(No trybots as this is a documentation only change)

BUG=none
R=sbc@chromium.org

Review URL: https://codereview.chromium.org/136273005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246381 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246381