Regularize ASSERT(imp) in bindings

Currently ASSERT(imp) is duplicated in the CG
(due to matching Perl code),
and located far from the actual initialization.
This puts the ASSERT in the right place,
and removes the duplication.

TBR=haraken
BUG=345503

Review URL: https://codereview.chromium.org/201583002

git-svn-id: svn://svn.chromium.org/blink/trunk@169329 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: do not flush front-end records if it has detached.

Review URL: https://codereview.chromium.org/201343004

git-svn-id: svn://svn.chromium.org/blink/trunk@169330 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Reapply: A thread-safe Media Query Parser

Originally reviewed here: https://codereview.chromium.org/171383002

Implement a thread-safe Media Query parser based on eseidel's tokenizer (https://codereview.chromium.org/123053002/).

This CL is composed of 2 parts:
* Rendering the MediaQuery related classes thread-safe, by eliminating AtomicStrings and replacing them with hash comparisons.
* Replacing BisonCSSParser for a new parser for MQ parsing.

TBR=eseidel@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/201423003

git-svn-id: svn://svn.chromium.org/blink/trunk@169331 bbb929c8-8fbe-4397-9dbb-9b2b20218538