Made double-tap zoom work in pinch virtual viewport mode (Chromium-side).

Made double-tap zoom work in pinch virtual viewport mode (Chromium-side).

On the Blink side:
The clamping method used by computeScaleAndScrollForBlockRect now
uses a new method PinchViewport::clampDocumentOffsetAtScale to clamp
the requested viewport offset taking into account the inner and outer
viewports.

Also added an overload of applyViewportDeltas, called in virtual
viewport mode only, that applies the inner and outer deltas along
page scale in one shot. This makes the viewport layers a special case
again in that their scroll offsets are set through this call, rather
than the standard 'did_scroll' callback of most layers. This is needed
since the scroll offsets may be invalid until the page scale is
applied so this is handled in one method to prevent unintended
clamping.

On the Compositor side:
Calls the appropriate applyViewportDeltas based on which pinch mode
we're running in. The page scale animation now prefers to scroll the
inner viewport first, scrolling the outer only when the inner has
reached its scroll extent.

Blink-side: https://codereview.chromium.org/584833003

BUG=364106
Committed: https://crrev.com/59379b09a4cbc478ce8e72db7bc658d9a8421ef5
Cr-Commit-Position: refs/heads/master@{#297167}

[bokan, 2014-09-19 20:00:58]

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

[bokan, 2014-09-19 20:00:59]

Alexandre, working on tests now but PTAL at this and the Blink-side patch.

[bokan, 2014-09-23 00:49:57]

Hey Alex, PTAL at this side too. Thanks.

[aelias_OOO_until_Jul13, 2014-09-23 01:07:42]

lgtm

[bokan, 2014-09-23 12:44:20]

bokan@chromium.org changed reviewers:
+ avi@chromium.org, jamesr@chromium.org

[bokan, 2014-09-23 12:44:20]

+jamesr@ for mojo/
+avi@ for content/renderer content/tests and ui/compositor

[Avi (use Gerrit), 2014-09-23 14:09:55]

The content side is just plumbing that LGTM.

[jamesr, 2014-09-23 23:32:23]

lgtm

[bokan, 2014-09-24 17:32:10]

The CQ bit was checked by bokan@chromium.org

[commit-bot: I haz the power, 2014-09-24 17:32:33]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/585063002/40001

[commit-bot: I haz the power, 2014-09-24 17:47:44]

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

[commit-bot: I haz the power, 2014-09-24 17:47:45]

Try jobs failed on following builders:
  linux_chromium_gn_rel on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[bokan, 2014-09-24 18:17:01]

The CQ bit was checked by bokan@chromium.org

[commit-bot: I haz the power, 2014-09-24 18:17:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/585063002/60001

[commit-bot: I haz the power, 2014-09-24 18:36:26]

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

[commit-bot: I haz the power, 2014-09-24 18:36:27]

Try jobs failed on following builders:
  android_aosp on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_aosp/bu...)
  android_dbg_tests_recipe on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_dbg_tes...)
  linux_chromium_gn_rel on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  linux_chromium_rel_swarming on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  mac_chromium_rel_swarming on tryserver.chromium.mac
(http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[bokan, 2014-09-24 19:20:52]

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

[bokan, 2014-09-24 19:20:53]

+mkosiba@ for build fix in android_webview

[mkosiba (inactive), 2014-09-29 10:41:27]

android_webview/ LGTM

[bokan, 2014-09-29 12:56:24]

The CQ bit was checked by bokan@chromium.org

[commit-bot: I haz the power, 2014-09-29 12:57:14]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/585063002/100001

[commit-bot: I haz the power, 2014-09-29 13:47:29]

Committed patchset #6 (id:100001) as f45f6fd2d77602bdceac54f7535571095d77e770

[commit-bot: I haz the power, 2014-09-29 13:48:10]

Patchset 6 (id:??) landed as
https://crrev.com/59379b09a4cbc478ce8e72db7bc658d9a8421ef5
Cr-Commit-Position: refs/heads/master@{#297167}