The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/cc1222ce4c3c615a49e689e7a35c5b36abe34e30

commit cc1222ce4c3c615a49e689e7a35c5b36abe34e30
Author: Ria Jiang <riajiang@chromium.org>
Date: Wed Feb 28 19:43:33 2018

Change HitTestQuery to operate in floating point and add short circuit.

1. Changed HitTestQuery to operate in floating point for precision and
updated tests.

2. Re-enabled SitePerProcessNonIntegerScaleFactorHitTestBrowserTest.
MouseClickWithNonIntegerScaleFactor for viz hit-test.

3. Previously, SitePerProcessNonIntegerScaleFactorHitTestBrowserTest.
MouseClickWithNonIntegerScaleFactor/0 actually went into the short
circuit block (when there's only one RenderWidgetHostView) for non-viz
hit-test, so it was not testing targeting. Added
SitePerProcessNonIntegerScaleFactorHitTestBrowserTest.
NestedSurfaceHitTestTest to test targeting for non-integer DSF.

4. Moved short circuit block to be for both viz hit-test and non-viz
hit-test (tested MouseClickWithNonIntegerScaleFactor for viz hit-test
before adding this short circuit).

Bug:  816746 
Test: site_per_process_hit_test_browsertests viz_unittests
Cq-Include-Trybots: master.tryserver.chromium.android:android_optional_gpu_tests_rel
Change-Id: I0bbefff2d1ca0367fa28c17df586f63d7a925114
Reviewed-on: https://chromium-review.googlesource.com/938964
Commit-Queue: Ria Jiang <riajiang@chromium.org>
Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Cr-Commit-Position: refs/heads/master@{#539930}
[modify] https://crrev.com/cc1222ce4c3c615a49e689e7a35c5b36abe34e30/components/viz/host/hit_test/hit_test_query.cc
[modify] https://crrev.com/cc1222ce4c3c615a49e689e7a35c5b36abe34e30/components/viz/host/hit_test/hit_test_query.h
[modify] https://crrev.com/cc1222ce4c3c615a49e689e7a35c5b36abe34e30/components/viz/host/hit_test/hit_test_query_unittest.cc
[modify] https://crrev.com/cc1222ce4c3c615a49e689e7a35c5b36abe34e30/content/browser/renderer_host/render_widget_host_input_event_router.cc
[modify] https://crrev.com/cc1222ce4c3c615a49e689e7a35c5b36abe34e30/content/browser/site_per_process_hit_test_browsertest.cc
[modify] https://crrev.com/cc1222ce4c3c615a49e689e7a35c5b36abe34e30/services/ui/ws/event_targeter.cc
[modify] https://crrev.com/cc1222ce4c3c615a49e689e7a35c5b36abe34e30/testing/buildbot/filters/mojo.fyi.viz.content_browsertests.filter
[modify] https://crrev.com/cc1222ce4c3c615a49e689e7a35c5b36abe34e30/testing/buildbot/filters/viz.content_browsertests.filter