Update How WebViewTest.ReloadAfterCrash waits for frames

WebViewTest.ReloadAfterCrash wants to wait for frames to have been produced, but
is not interested in hit test data.

It has been using WaitForChildFrameSurfaceReady which does not work with
VizDisplayCompositor.

This updates it to using RenderFrameSubmissionObserver which works with both
classic compositing and Viz.

TEST=WebViewTest.ReloadAfterCrash

Bug: 787945
Change-Id: I1358b0780964cff0298f6e8851dd629bbd14dc44
Reviewed-on: https://chromium-review.googlesource.com/1076778
Reviewed-by: Fady Samuel <fsamuel@chromium.org>
Commit-Queue: Jonathan Ross <jonross@chromium.org>
Cr-Commit-Position: refs/heads/master@{#562837}
2 files changed