Revert 245663 "Revert 245645 "Define WebScrollOffsetAnimationCur..."

Revert 245663 "Revert 245645 "Define WebScrollOffsetAnimationCur..."

> Revert 245645 "Define WebScrollOffsetAnimationCurveImpl"
> 
> Broke compositor_unittests on Linux Aura Tests with error:

I'm a dirty liar.

> 
>   LayerWithRealCompositorTest.DrawPixels (run #1):
>   [ RUN      ] LayerWithRealCompositorTest.DrawPixels
>   ../../ui/compositor/layer_unittest.cc:832: Failure
>   Value of: ReadPixels(&bitmap, gfx::Rect(viewport_size))
>     Actual: false
>   Expected: true
>   [  FAILED  ] LayerWithRealCompositorTest.DrawPixels (246 ms)
> 
>   LayerWithRealCompositorTest.DrawPixels (run #2):
>   [ RUN      ] LayerWithRealCompositorTest.DrawPixels
>   ../../ui/compositor/layer_unittest.cc:832: Failure
>   Value of: ReadPixels(&bitmap, gfx::Rect(viewport_size))
>     Actual: false
>   Expected: true
>   [  FAILED  ] LayerWithRealCompositorTest.DrawPixels (272 ms)
> 
>   LayerWithRealCompositorTest.DrawPixels (run #3):
>   [ RUN      ] LayerWithRealCompositorTest.DrawPixels
>   ../../ui/compositor/layer_unittest.cc:832: Failure
>   Value of: ReadPixels(&bitmap, gfx::Rect(viewport_size))
>     Actual: false
>   Expected: true
>   [  FAILED  ] LayerWithRealCompositorTest.DrawPixels (259 ms)
> 
>   LayerWithRealCompositorTest.DrawPixels (run #4):
>   [ RUN      ] LayerWithRealCompositorTest.DrawPixels
>   ../../ui/compositor/layer_unittest.cc:832: Failure
>   Value of: ReadPixels(&bitmap, gfx::Rect(viewport_size))
>     Actual: false
>   Expected: true
>   [  FAILED  ] LayerWithRealCompositorTest.DrawPixels (229 ms)
> 
> > Define WebScrollOffsetAnimationCurveImpl
> > 
> > This defines WebScrollOffsetAnimationCurveImpl, which wraps a
> > cc::ScrollOffsetAnimationCurve. This is needed for
> > implementing the CSSOM Smooth Scroll API.
> > 
> > BUG=243871
> > 
> > Review URL: https://codereview.chromium.org/112933005
> 
> TBR=ajuma@chromium.org
> 
> Review URL: https://codereview.chromium.org/141753007

TBR=dbeam@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=245674

[Dan Beam, 2014-01-18 00:28:24]

Committed patchset #1 manually as r245674 (tree was closed).