Use resource throttle to implement shouldOverrideUrlLoading, core change
We have been using both a resource throttle and a sync IPC to implement
shouldOverrideUrlLoading, with this patch we use only a resource
throttle instead.
This patch depends on https://codereview.chromium.org/
1194383003 which
adds a flag indicating that the current request was overridden. The flag
is passed down to AwWebContentsObserver.didFailLoad. That CL in turn
depends on https://codereview.chromium.org/
1178273007/ which adds the
flag to blink errors.
BUG=325351
Review URL: https://codereview.chromium.org/
1155713005
Cr-Commit-Position: refs/heads/master@{#339109}