Make sure INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT is created when event passes through RWHI

We want every input event to have a INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT
in its LatencyInfo as the starting point for measuring input latency. In some
test cases the synthetic mouse/mouse wheel event can miss the component:
For example, for non-aura platform,
SyntheticGestureTargetBase::DispatchWebMouseWheelEventToPlatform calls
RWHI::ForwardWheelEventWithLatencyInfo(), while we only enforcing creating
the begin component in RWHI::ForwardWheelEvent().

The fix in this CL is to move CreateRWHLatencyInfoIfNotExist() call, which
enforces that the begin component exists/is created in the LatencyInfo, from
RWHI::ForwardWheelEvent into RWHI::ForwardWheelEventWithLatencyInfo.

The same is applied to FowardMouseEvent(WithLatencyInfo)().

BUG=246034
TEST=run telemtry smoothness test agasint non-aura linux build, and make sure
     that INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT exists for mouse wheel event's
     LatencyInfo.

Review URL: https://codereview.chromium.org/136203003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246257 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246257
Excludes ResolutionNotificationController for non-ChromeOS.

This feature is ChromeOS specific.

BUG=none
R=oshima@chromium.org

Review URL: https://codereview.chromium.org/137203008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246258 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246258
Check that directory named depot_tools appears to be full checkout

When running recipes on build slaves, the PYTHONPATH has many (many!)
things injected, one of which includes a partial checkout of
depot_tools. As a result, find_depot_tools got confused as it thought
it had found the correct directory while searching, but then failed
to import breakpad.

This makes the search at least confirm there's a file named
breakpad.py present so the later import will probably succeed.

R=phajdan.jr@chromium.org

Review URL: https://codereview.chromium.org/137203009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246259 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246259