DevTools: [CodeMirror] fix autodetect feature

This patch fixes a bug in autodetection feature which
caused it work incorrectly on some large files.

BUG=

Review URL: https://chromiumcodereview.appspot.com/21264006

git-svn-id: svn://svn.chromium.org/blink/trunk@155317 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Revert "Remove the pointer from StringImpl"

This reverts commit 83f31bb9cdcb97a23eccf89f5e9b00d894024345.
It seems to break many tests crash on Win7 dbg.

TBR=abarth
BUG=

Review URL: https://codereview.chromium.org/21504002

git-svn-id: svn://svn.chromium.org/blink/trunk@155318 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Cleanup use of return value in StringCache

R=jochen@chromium.org
BUG=

ReturnValue is intended to be passed by value into any function that's not inlined or doesn't need access to stuff in FunctionCallbackInfo or PropertyCallbackInfo.

Review URL: https://chromiumcodereview.appspot.com/21022012

git-svn-id: svn://svn.chromium.org/blink/trunk@155319 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Adding NeedsRebaseline for Mac ImageOnlyFailure bugs.

TBR=ccameron
BUG=

Review URL: https://codereview.chromium.org/20745005

git-svn-id: svn://svn.chromium.org/blink/trunk@155320 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Mark fast/ruby/ruby-svg-crash.html as ImageOnlyFailure Pass.

TBR=pdr
BUG=

Review URL: https://codereview.chromium.org/21510002

git-svn-id: svn://svn.chromium.org/blink/trunk@155321 bbb929c8-8fbe-4397-9dbb-9b2b20218538
WebCrypto: Check that the key can be used for given operation.

 * key.usages must allow the operation
 * key.algorithm must match the specified operation

BUG=245025

Review URL: https://chromiumcodereview.appspot.com/20843008

git-svn-id: svn://svn.chromium.org/blink/trunk@155322 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Make CharacterData.appendData() argument mandatory

Make CharacterData.appendData() argument mandatory as per the latest specification:
http://dom.spec.whatwg.org/#characterdata

This behavior is consistent with IE10 and Firefox.

BUG=266351

Review URL: https://chromiumcodereview.appspot.com/21364003

git-svn-id: svn://svn.chromium.org/blink/trunk@155323 bbb929c8-8fbe-4397-9dbb-9b2b20218538