SyntheticGestureTarget implementation for injecting synthetic input events.

This will be used from SyntheticGesture implementations such as SyntheticSmoothScrollGesture(New) to inject input events in a Android/aura specific way. The patch also includes fallback implementation in SyntheticGetsureTargetBase which passes the input events to RWH.

BUG=297960
BUG=306459

Review URL: https://codereview.chromium.org/26664002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@234354 0039d316-1c4b-4281-b951-d872f2087c98
[chromedriver] Add a python test for checking that latest android app is installed.

BUG=None
R=craigdh@chromium.org

Review URL: https://codereview.chromium.org/67483002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@234355 0039d316-1c4b-4281-b951-d872f2087c98
Some more debug logging for extension loading failure.

* print chrome cmd line
* take a screenshot
* increase logging of extension code
* wait for extensions after opening a browser window

BUG=304442
TEST=Manual
NOTRY=True

Review URL: https://codereview.chromium.org/59873005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@234356 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 234356