Decouple the Custom Elements web platform feature and embedder feature.

Chrome Apps V2 implements <webview> as a Custom Element by flipping
on the Custom Elements feature, but in a limited mode where it only
accepts specific tag names. This breaks author script which tries to
do feature detection of Custom Elements, because document.register is
present, but acting in lame-duck mode.

This patch adds a specific API for embedders to define Custom
Elements. The API surface is independent of the web platform feature
so that they can be used in isolation or both at the same time.

BUG=273126

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=156331

Review URL: https://chromiumcodereview.appspot.com/22854017

git-svn-id: svn://svn.chromium.org/blink/trunk@156403 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add support for DOM Level 3 WheelEvent

Add support for DOM Level 3 WheelEvent:
http://www.w3.org/TR/DOM-Level-3-Events/#events-WheelEvent

Full support is implemented except for the DeltaZ property which had
no equivalent in the previous 'mousewheel' event.

Firefox and IE10 already support it so it increases our cross-browser
compatibility.

The non-standard 'mousewheel' event is still supported for backward
compatibility.

BUG=227454

Review URL: https://chromiumcodereview.appspot.com/22859012

git-svn-id: svn://svn.chromium.org/blink/trunk@156404 bbb929c8-8fbe-4397-9dbb-9b2b20218538
More refactoring to get rid of DOMDataStore::getWrapper call sites.

It's unsafe handle access and going away.

BUG=236290

Review URL: https://chromiumcodereview.appspot.com/22964006

git-svn-id: svn://svn.chromium.org/blink/trunk@156405 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add a --no-android-logging flag to run-webkit-tests.

Currently we log every single adb command as part of --debug-rwt-logging
when running the tests on the android port. This makes the log very
verbose, and most of the time this is noise. This patch adds a way to
turn that logging off, though it is still on by default. Eventually we
should flip the default to have to turn the logging on (or get rid of
the logging altogether), but there's some clean up of logging that is
actually useful that should happen first.

R=peter@chromium.org, ojan@chromium.org, abarth@chromium.org
BUG=

Review URL: https://chromiumcodereview.appspot.com/22980017

git-svn-id: svn://svn.chromium.org/blink/trunk@156406 bbb929c8-8fbe-4397-9dbb-9b2b20218538