Fix bump-scroll.
Fix bump-scroll.

Apply bump scroll to the entire client-plugin-render hierarchy, not just
the plugin, which doesn't handle rendering when MediaSource is enabled.

BUG=411996
TBR=sergeyu

Review URL: https://codereview.chromium.org/558283002

Cr-Commit-Position: refs/heads/master@{#294267}
(cherry picked from commit 73dafe3a8b7084b33fb93aefb1588056e076775f)

Review URL: https://codereview.chromium.org/563543003

Cr-Commit-Position: 0d344d3782ceeadf0e8e8be3f4ce70193b218c54@{#315}
Cr-Branched-From: 2cb3f0147827a1600e8cbbcc52ca24c0febcb7a4@{#290040}

littlstar/chromium.src,bright-sparks/chromium-spacewalk,littlstar/chromium.src,ondra-novak/chromium.src,ondra-novak/chromium.src,bright-sparks/chromium-spacewalk,bright-sparks/chromium-spacewalk,ondra-novak/chromium.src,bright-sparks/chromium-spacewalk,bright-sparks/chromium-spacewalk,bright-sparks/chromium-spacewalk,ondra-novak/chromium.src,ondra-novak/chromium.src,ondra-novak/chromium.src,ondra-novak/chromium.src,littlstar/chromium.src,littlstar/chromium.src,ondra-novak/chromium.src,littlstar/chromium.src,littlstar/chromium.src,ondra-novak/chromium.src,bright-sparks/chromium-spacewalk,bright-sparks/chromium-spacewalk,bright-sparks/chromium-spacewalk,littlstar/chromium.src,littlstar/chromium.src