Fix for no TYPE_VIEW_SCROLLED AccessibilityEvent on scrolling web page in Android

In version 29.0.1545.0, https://chromiumcodereview.appspot.com/16255010
removed onScrollChanged from ContentView.java and this caused having
no accessibility scroll event from ContentView when scrolling. Added onScrollChanged back to ContentView.java

BUG=296676

Review URL: https://codereview.chromium.org/26572003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230800 0039d316-1c4b-4281-b951-d872f2087c98
Remove temporary WebKitPlatformSupportImpl::addTraceEventNew

Final step of migrating WebKit TraceEvent to new API.

BUG=trace-viewer:487

Review URL: https://codereview.chromium.org/29323007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230801 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230800
PerformanceMonitor: Add a new UMA histograms to track average CPU utilization of the browser process

R=asvitkine@chromium.org, yoz@chromium.org
BUG=306713

Review URL: https://codereview.chromium.org/29873002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230802 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230802
Convert views X11 UnhandledKeyboardEventHandler to other Linux platforms

We have two Linux platforms supported under Aura: Ozone and X11. The files
being changed on this CL don't touch any X11 specific code, so they can used by Ozone as well.

Linux GTK+ takes another path, not using views, so this change doesn't affect that.

BUG=295089

Review URL: https://codereview.chromium.org/34573002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230803 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230803