DevTools: Enable toolbar customization.

Allow add/remove selected set of tools on the toolbar. The new
behavior is put behind an experiment.

BUG=229418
R=pfeldman@chromium.org
NOTRY=true

Review URL: https://chromiumcodereview.appspot.com/13818009

git-svn-id: svn://svn.chromium.org/blink/trunk@148285 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: [CodeMirror] CodeMirror is stuck on startup

Fix CodeMirrorTextEditor to forward focus to CodeMirror instance.

BUG=

Review URL: https://chromiumcodereview.appspot.com/13995004

git-svn-id: svn://svn.chromium.org/blink/trunk@148286 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: hide switch panel shortcut behind experiment

Move Ctrl/Cmd + 1-9 shortcut which switches panels into
experiments.

BUG=

Review URL: https://chromiumcodereview.appspot.com/13951006

git-svn-id: svn://svn.chromium.org/blink/trunk@148287 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Flatten Archive and MHTMLArchive into a single class, since we now have only
one type of Archive.

BUG=none
TEST=none
Review URL: https://codereview.chromium.org/14194004

git-svn-id: svn://svn.chromium.org/blink/trunk@148288 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove the CANVAS_PATH compile-time flag.

This mechanical change should have no web-visible impact, as Chromium always
enables this flag.

Review URL: https://codereview.chromium.org/14225002

git-svn-id: svn://svn.chromium.org/blink/trunk@148289 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Various duplicate/obsolete warnings were cleaned up/removed

* chromium-android's TestExpectations referred to deleted directories
* chromium's TestExpectations had redundant entries for several tests

Review URL: https://codereview.chromium.org/13812018

git-svn-id: svn://svn.chromium.org/blink/trunk@148290 bbb929c8-8fbe-4397-9dbb-9b2b20218538