[Android] Always complete a TapDown gesture with TapCancel if necessary

A TapDown gesture should always be accompanied by a tap-ending event.
Previously, ShowPress gestures were tracked by ContentViewGestureHandler to
indicate if a TapCancel event was necessary.  However, the addition of an
immediate TapDown supercedes this requirement.  Send synthetic TapCancel if
necessary to complete the TapDown.

BUG=313830

Review URL: https://codereview.chromium.org/55313004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233128 0039d316-1c4b-4281-b951-d872f2087c98
Include the pid in the common crash keys

This makes it easier to locate a minidump corresponding to a given crash
when running layout tests

BUG=none
R=rsesek@chromium.org

Review URL: https://codereview.chromium.org/55903006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233129 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 233129