Automatically applying components based on crash stacktrace and information from OWNERS files.

If this is incorrect, please apply the Test-Predator-Wrong-Components label.

Automatically adding ccs based on suspected regression changelists:

Replace WTF::MakeUnique with std::make_unique on core/exported, core/frame/ and core/loader/ by lucmult@chromium.org - https://chromium.googlesource.com/chromium/src/+/804cf422e9b43d32ef56d630b6ed762bbd6403d1

Scroll anchor serialization skeleton by pnoland@google.com - https://chromium.googlesource.com/chromium/src/+/2352f5672ed01cdbdd6f9fecb3fdd1a625a9fbfc

Split WTF::CrossThreadFunction out of WTF::Function. by yutak@chromium.org - https://chromium.googlesource.com/chromium/src/+/f3ce2901174c13c13a318dc68f5473cad413199b

If this is incorrect, please let us know why and apply the Test-Predator-Wrong-CLs label.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/48ec74d7989862a82990827d4898d016d2942615

commit 48ec74d7989862a82990827d4898d016d2942615
Author: David Bokan <bokan@chromium.org>
Date: Thu Mar 01 18:36:14 2018

[root-layer-scrolls] Fix android fullscreen video

Android uses an "overlay" composited video layer when a video is
fullscreened. This layer is parented to the PaintLayerCompositor's
root_content_layer and the actual content (LayoutView) is detached.

With root-layer-scrolling enabled, PLC doesn't create a
root_content_layer and the top-most GraphicsLayer in PLC is that of the
LayoutView. This CL connects the video layer to the PLC's parent
instead. This is currently the outer viewport scroll layer. We also need
to make sure painting starts from the child of this layer, rather than
the PLC's root layer since the video layer is no longer connected to the
root. This doesn't matter for the video itself, however, the media
player controls need to be painted from Blink.

These changes exposed some brittleness in the compositor and the Android
fullscreen video layout tests were hitting the DCHECK in
ScrollbarLayerImplBase::CanScrollOrientation. This is because the
viewport scrollbars use the outer/layout viewport as their ElementId but
are owned by the inner/visual viewport. So when we disconnect the PLC's
content layers, we remove the ScrollNode in the compositor but the
visual viewport and its scrollbar layers live on. The rest of this patch
changes the visual viewport scrollbars to use the visual viewport's
element id.

TEST=virtual/android/fullscreen/video-scrolled-iframe.html,
     virtual/android/fullscreen/video-controls-timeline.html,
     virtual/android/fullscreen/full-screen-iframe-allowed-video.html

Bug:  711468 , 811024 
Cq-Include-Trybots: 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
Change-Id: Ic1c52e1853f14842ee3ae19119476b8945ecae17
Reviewed-on: https://chromium-review.googlesource.com/923397
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Commit-Queue: Chris Harrelson <chrishtr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#540226}
[modify] https://crrev.com/48ec74d7989862a82990827d4898d016d2942615/cc/input/scrollbar_animation_controller.cc
[modify] https://crrev.com/48ec74d7989862a82990827d4898d016d2942615/cc/trees/layer_tree_host_impl.cc
[modify] https://crrev.com/48ec74d7989862a82990827d4898d016d2942615/cc/trees/layer_tree_impl.cc
[modify] https://crrev.com/48ec74d7989862a82990827d4898d016d2942615/third_party/WebKit/LayoutTests/TestExpectations
[modify] https://crrev.com/48ec74d7989862a82990827d4898d016d2942615/third_party/WebKit/Source/core/exported/WebViewImpl.cpp
[modify] https://crrev.com/48ec74d7989862a82990827d4898d016d2942615/third_party/WebKit/Source/core/frame/LocalFrameView.cpp
[modify] https://crrev.com/48ec74d7989862a82990827d4898d016d2942615/third_party/WebKit/Source/core/frame/VisualViewport.cpp
[modify] https://crrev.com/48ec74d7989862a82990827d4898d016d2942615/third_party/WebKit/Source/core/frame/VisualViewport.h
[modify] https://crrev.com/48ec74d7989862a82990827d4898d016d2942615/third_party/WebKit/Source/core/paint/compositing/PaintLayerCompositor.cpp
[modify] https://crrev.com/48ec74d7989862a82990827d4898d016d2942615/third_party/WebKit/Source/core/paint/compositing/PaintLayerCompositor.h

^^^ Sorry, wrong bug #

ClusterFuzz testcase 5233792286195712 is flaky and no longer crashes, so closing issue.

If this is incorrect, please add ClusterFuzz-Wrong label and re-open the issue.