All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=823514

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=5bfb31067676b881804e732ba0a83e179f4b5b46e21c951e66c1bdee92a1868e


Bot(s) for this bug's original alert(s):

android-webview-nexus6

Assigning to junov@chromium.org because this is the only CL in range:
Automate calls to GrContext::resetContext

The purpose of this change is to prevent the re-occurrence of flaky
rendering bugs caused by missing calls to GrContext::resetContext. This
change uses a new subclass of GLES2Implementation called
GLES2ImplementationWithGrContextSupport, which takes care of calling
GrContext::resetContext() whenever the gl state is changed. These
calls are lightweight: they just perform an 'or' on an integer.

To avoid calling GrContext::resetContext() when gl calls are made from
within skia, the bindings were modified in CreateGLES2InterfaceBindings
in order to signal the GLES2ImplementationWithGrContextSupport so that
it knows the the current GL call is made from skia.

Cq-Include-Trybots: luci.chromium.try:linux_optional_gpu_tests_rel;master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: I59470a8188df235a36d6de0e9aaff57b69ff9d6a
Bug:  807974 ,  810159 
Reviewed-on: https://chromium-review.googlesource.com/924616
Commit-Queue: Justin Novosad <junov@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Antoine Labour <piman@chromium.org>
Reviewed-by: Fredrik Hubinette <hubbe@chromium.org>
Reviewed-by: Brian Salomon <bsalomon@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Reviewed-by: Bo <boliu@chromium.org>
Reviewed-by: Fernando Serboncini <fserb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#543955}