Revert of Pinch/Zoom Infrastructure & Plumbing CL (https://codereview.chromium.org/23983047/)
Reason for revert:
This patch broke several blink-side compositing/rtl tests[1][2]. It's
unclear whether these tests are valuable, given some comments
in TestExpectations, but since I know nothing about compositing
I'll leave the decision about what to do with these tests up to
someone who does.
[1]: http://test-results.appspot.com/dashboards/flakiness_dashboard.html#group=%40ToT%20Blink&tests=compositing/rtl/rtl-iframe-absolute-overflow-scrolled.html,compositing/rtl/rtl-iframe-absolute-overflow.html,compositing/rtl/rtl-iframe-fixed-overflow-scrolled.html,compositing/rtl/rtl-iframe-fixed-overflow.html
[2]: http://build.chromium.org/p/chromium.webkit/builders/WebKit%20Mac10.7/builds/22131
Original issue's description:
> Pinch/Zoom Infrastructure & Plumbing CL
>
> This CL supplies the necessary changes to CC to support the
> inner/outer viewport model for pinch-zoom and fixed-position
> elements. The specification for these changes is contained in
> the document "Layer-based Solution for Pinch Zoom / Fixed
> Position".
>
> It incorporates a change to how scrollbar parameters are
> computed (removes the notion of max_scroll_offset as a
> quantity set be the embedder, and instead inferred from the
> relative sizes of a clip layer w.r.t. the scroll layer).
>
> Scrollbars are generalized so that a layer may have more than
> two scrollbars, and the parameters of the scrollbar are set
> w.r.t. the sizes and positions of a clip and a scroll layer.
> Further, changes to the scrip/scroll layer automatically
> notify any attached scrollbars.
>
> The CL also removes existing references to root_scroll_layer
> from LTH, LTI and LTHI and replaces them with either
> Inner/OuterViewportScrollLayer (dual-layer operation only
> exists at present if the --enable-pinch-virtual-viewport flag
> is specified, otherwise behavior is unchanged).
>
> Logic is added to (i) combine scroll offsets for the two
> viewports before passing it to the embedder, and (ii)
> splitting any offsets received from the embedder
> appropriately between the two viewports.
>
> This CL relies on https://codereview.chromium.org/138453004/
> for changes in Blink to support it.
>
> BUG=148816
>
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=246812
TBR=enne@chromium.org,aelias@chromium.org,joi@chromium.org,sky@chromium.org,piman@chromium.org,tony@chromium.org,wjmaclean@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=148816
Review URL: https://codereview.chromium.org/146713002
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246842 0039d316-1c4b-4281-b951-d872f2087c98
49 files changed
