Make error-handling for feColorMatrix consistent

Make error-handling for feColorMatrix consistent

After/with https://codereview.chromium.org/1087283002, error-handling
for feColorMatrix will differ based on when the error occured (in
"initial" content, or through later script mutation; "initial" meaning
the state on first paint).
Align the two different code-paths by removing error-handling entirely
from one of them (SVGFEColorMatrixElement::build) building on the CL
mentioned above.

Also take this opportunity to align our error-handling behavior with
Gecko:
 * Excess 'values' for type='matrix' => use identity
 * Excess 'values' for type='saturate'/'huerotate' => use identity

The test svg/filterS/feColorMatrix-values.svg is updated to reflect the
above, and is converted to a ref-test while at it.
Tweak the DRT output for FEColorMatrix to only output 'values' if they
are valid and actually used.

BUG=534763, 533457
TBR=senorblanco@chromium.org,fmalita@chromium.org

Committed: https://crrev.com/e24b4c8d9dec1cb492d8a3e14d465329dd426a77
Cr-Commit-Position: refs/heads/master@{#350607}

[fs, 2015-09-24 14:53:04]

fs@opera.com changed reviewers:
+ fmalita@chromium.org, senorblanco@chromium.org

[fs, 2015-09-24 16:17:49]

The CQ bit was checked by fs@opera.com

[commit-bot: I haz the power, 2015-09-24 16:18:30]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1366903002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1366903002/1

[Stephen White, 2015-09-24 16:19:58]

LGTM

https://codereview.chromium.org/1366903002/diff/1/third_party/WebKit/LayoutTe...
File third_party/WebKit/LayoutTests/TestExpectations (right):

https://codereview.chromium.org/1366903002/diff/1/third_party/WebKit/LayoutTe...
third_party/WebKit/LayoutTests/TestExpectations:177: crbug.com/534763
css3/filters/effect-reference-hw.html [ NeedsRebaseline ]
How are these tests affected, BTW? Did they have error conditions in their
feColorMatrix elements? If so, could we fix them instead?

[f(malita), 2015-09-24 16:24:07]

LGTM 2

[fs, 2015-09-24 16:30:33]

https://codereview.chromium.org/1366903002/diff/1/third_party/WebKit/LayoutTe...
File third_party/WebKit/LayoutTests/TestExpectations (right):

https://codereview.chromium.org/1366903002/diff/1/third_party/WebKit/LayoutTe...
third_party/WebKit/LayoutTests/TestExpectations:177: crbug.com/534763
css3/filters/effect-reference-hw.html [ NeedsRebaseline ]
On 2015/09/24 at 16:19:57, Stephen White wrote:
> How are these tests affected, BTW? Did they have error conditions in their
feColorMatrix elements? If so, could we fix them instead?

There's no longer an (explicit) identity matrix in the DRT output, so all of
these are basically:

-[feColorMatrix type=MATRIX values="1.00 0.00 ..."]
+[feColorMatrix type=MATRIX]

Which stems from <feColorMatrix>es without a type (or values).

So no error condition - just different dumping of default values.

[Stephen White, 2015-09-24 17:21:36]

On 2015/09/24 16:30:33, fs wrote:
>
https://codereview.chromium.org/1366903002/diff/1/third_party/WebKit/LayoutTe...
> File third_party/WebKit/LayoutTests/TestExpectations (right):
> 
>
https://codereview.chromium.org/1366903002/diff/1/third_party/WebKit/LayoutTe...
> third_party/WebKit/LayoutTests/TestExpectations:177: crbug.com/534763
> css3/filters/effect-reference-hw.html [ NeedsRebaseline ]
> On 2015/09/24 at 16:19:57, Stephen White wrote:
> > How are these tests affected, BTW? Did they have error conditions in their
> feColorMatrix elements? If so, could we fix them instead?
> 
> There's no longer an (explicit) identity matrix in the DRT output, so all of
> these are basically:
> 
> -[feColorMatrix type=MATRIX values="1.00 0.00 ..."]
> +[feColorMatrix type=MATRIX]
> 
> Which stems from <feColorMatrix>es without a type (or values).
> 
> So no error condition - just different dumping of default values.

Makes sense. Thanks for the explanation!

[commit-bot: I haz the power, 2015-09-24 18:12:37]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-09-24 18:14:08]

Patchset 1 (id:??) landed as
https://crrev.com/e24b4c8d9dec1cb492d8a3e14d465329dd426a77
Cr-Commit-Position: refs/heads/master@{#350607}