GitLab

Use NavigationPolicyThrottle and NavigationPolicyHandler in FrameImpl
and WebEngineContentRendererClient so the new functionality is exposed
to clients

Tests: NavigationPolicyTest
Bug: 1117601
Change-Id: If4b96b72b60792912f071513562bec0d0f920254
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2504581
Commit-Queue: Sharon Yang <yangsharon@chromium.org>
Reviewed-by: David Dorwin <ddorwin@chromium.org>
Reviewed-by: Sergey Ulanov <sergeyu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#827137}