GitLab

from https://chromiumcodereview.appspot.com/190693002/

This patch makes Page.captureScreenshot synchronize with the renderer.
When fixed implementation hits Stable it will be possible to use Page.captureScreenshot in Telemetry instead of window.chrome.gpuBenchmarking.beginWindowSnapshotPNG and remove the latter.

BUG=242405

Review URL: https://codereview.chromium.org/311313003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@278472 0039d316-1c4b-4281-b951-d872f2087c98