Remove obsolete pinch-zoom related code.

Remove obsolete pinch-zoom related code.

Removing some left over bits of code from the old path of pinch-zoom:

setMainFrameScrollOffset from the Blink public API - this is only used within
Blink internally.

Remove obsolete dead code from PinchViewport::setScaleAndLocation - forgot to
remove this when tearing out old path in r192391..

Remove VirtualViewport setting from WebSettings - now that the Chromium side
is removed, this is no longer needed.

BUG=304869
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=196313

[bokan, 2015-05-29 13:39:42]

bokan@chromium.org changed reviewers:
+ pdr@chromium.org

[bokan, 2015-05-29 13:39:43]

Hi PDR, bit of cleanup, ptal.

[pdr., 2015-05-29 18:14:28]

On 2015/05/29 at 13:39:43, bokan wrote:
> Hi PDR, bit of cleanup, ptal.

LGTM

[pdr., 2015-05-29 18:14:30]

The CQ bit was checked by pdr@chromium.org

[commit-bot: I haz the power, 2015-05-29 18:14:54]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1167503002/1

[bokan, 2015-05-29 19:18:22]

There's one svg layout test that was causing a crash with my change, looks like
SVG can run without accelerated compositing so I added a check rather an an
ASSERT. still l-g-t-m?

[bokan, 2015-06-01 18:45:01]

ping

[pdr., 2015-06-01 22:19:15]

LGTM

[bokan, 2015-06-02 10:35:03]

The CQ bit was checked by bokan@chromium.org

[commit-bot: I haz the power, 2015-06-02 10:35:32]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1167503002/20001

[commit-bot: I haz the power, 2015-06-02 12:32:16]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-06-02 12:32:17]

Try jobs failed on following builders:
  linux_blink_rel on tryserver.blink (JOB_FAILED,
http://build.chromium.org/p/tryserver.blink/builders/linux_blink_rel/builds/6...)

[bokan, 2015-06-02 13:15:36]

The CQ bit was checked by bokan@chromium.org

[commit-bot: I haz the power, 2015-06-02 13:15:51]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1167503002/20001

[commit-bot: I haz the power, 2015-06-02 14:01:08]

Committed patchset #2 (id:20001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=196313