Fix external SkImageFilter caching with clips.

Fix external SkImageFilter caching with clips.

When the external cache is active, do not intersect the saveLayer
bounds with the clip bounds.  This is so that the cache is always the
full size of the primitive's bounds, regardless of the clip active on
first draw. (Drawing of the filtered or cached result is always drawn
against the active clip, though, since it is restored before
internalDrawDevice() is called.)

This is a slightly hacky solution, but this code can all go away
(including the external cache) once all platforms have switched to
impl-side painting.

See Chromium bug http://crbug.com/379147.

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/ffa9b500d7e83e7dddf6a8902f47c4355b608c30

[Stephen White, 2014-06-18 20:19:43]

reed@: PTAL. Thanks!

[reed1, 2014-06-18 20:27:54]

lgtm -- but desperately needs a comment in the code

https://codereview.chromium.org/340203002/diff/1/src/core/SkImageFilter.cpp
File src/core/SkImageFilter.cpp (right):

https://codereview.chromium.org/340203002/diff/1/src/core/SkImageFilter.cpp#n...
src/core/SkImageFilter.cpp:125: if (SkImageFilter::GetExternalCache()) {
Lets add a comment as to why this makes sense to do.

[Stephen White, 2014-06-18 20:39:34]

On 2014/06/18 20:27:54, reed1 wrote:
> lgtm -- but desperately needs a comment in the code
> 
> https://codereview.chromium.org/340203002/diff/1/src/core/SkImageFilter.cpp
> File src/core/SkImageFilter.cpp (right):
> 
>
https://codereview.chromium.org/340203002/diff/1/src/core/SkImageFilter.cpp#n...
> src/core/SkImageFilter.cpp:125: if (SkImageFilter::GetExternalCache()) {
> Lets add a comment as to why this makes sense to do.

Done.

[Stephen White, 2014-06-18 20:53:26]

Note to sheriff: this will require the following Chrome tests to be rebaselined
for minor pixel diffs:

  svg/W3C-SVG-1.1/filters-color-01-b.svg [ ImageOnlyFailure ]
  svg/W3C-SVG-1.1/filters-comptran-01-b.svg [ ImageOnlyFailure ]
  svg/batik/filters/feTile.svg [ ImageOnlyFailure ]
  svg/filters/big-sized-filter.svg [ ImageOnlyFailure ]
  svg/filters/feLighting-crash.svg [ ImageOnlyFailure ]

[reed1, 2014-06-18 20:58:24]

On 2014/06/18 20:53:26, Stephen White wrote:
> Note to sheriff: this will require the following Chrome tests to be
rebaselined
> for minor pixel diffs:
> 
>   svg/W3C-SVG-1.1/filters-color-01-b.svg [ ImageOnlyFailure ]
>   svg/W3C-SVG-1.1/filters-comptran-01-b.svg [ ImageOnlyFailure ]
>   svg/batik/filters/feTile.svg [ ImageOnlyFailure ]
>   svg/filters/big-sized-filter.svg [ ImageOnlyFailure ]
>   svg/filters/feLighting-crash.svg [ ImageOnlyFailure ]

Please land those in chrome now if possible, so we can continue to use the
auto-roller.

[Stephen White, 2014-06-18 21:43:15]

The CQ bit was checked by senorblanco@chromium.org

[commit-bot: I haz the power, 2014-06-18 21:43:35]

CQ is trying da patch. Follow status at

https://skia-tree-status.appspot.com/cq/senorblanco@chromium.org/340203002/20001

[commit-bot: I haz the power, 2014-06-18 22:11:29]

Change committed as ffa9b500d7e83e7dddf6a8902f47c4355b608c30