Update references to Blink's Platform API headers (remaining)

Update references to Blink's Platform API headers (remaining)

These headers have moved from Source/Platform/chromium/public to
public/platform. This CL updates the remaining references to the old location
to point to the new location. After this CL lands, I'll remove the forwarding
headers that are letting these references still work.

TBR=darin@chromium.org
BUG=239545
NOTRY=true

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=203106

[commit-bot: I haz the power, 2013-05-30 05:00:37]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/abarth@chromium.org/15648012/1

[commit-bot: I haz the power, 2013-05-30 07:09:12]

Retried try job too often on linux_aura for step(s) browser_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_aura...

[commit-bot: I haz the power, 2013-05-30 07:12:57]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/abarth@chromium.org/15648012/1

[commit-bot: I haz the power, 2013-05-30 07:56:52]

Change committed as 203106