Adjust the alpha type for pixelRefs.

Adjust the alpha type for pixelRefs.

Move SkBitmap's validate_alphaType to SkImageInfo, with the new
name SkColorTypeValidateAlphaType. Use it in SkPixelRef's constructors,
as well as in SkDecodingImageGenerator. This fixes a bug where an
SkPixelRef's SkAlphaType could get out of sync with its SkBitmap,
when both were assigned the same SkAlphaType.

Committed: https://skia.googlesource.com/skia/+/2fd0d14b9be34a7a945942733c3516d97d07f516

[scroggo, 2014-06-18 17:45:43]

https://codereview.chromium.org/346593003/diff/1/include/core/SkImageInfo.h
File include/core/SkImageInfo.h (right):

https://codereview.chromium.org/346593003/diff/1/include/core/SkImageInfo.h#n...
include/core/SkImageInfo.h:123: *  Return true if alphaType is supported by
colorType. If there is a canonical
Let me know if you think there is a better way to express this. It appears we
only return false if someone paired kIgnore_SkAlphaType (which may be going
away, IIUC?) with a valid SkColorType, or if they used an invalid SkColorType.

[reed1, 2014-06-18 17:58:20]

https://codereview.chromium.org/346593003/diff/1/include/core/SkImageInfo.h
File include/core/SkImageInfo.h (right):

https://codereview.chromium.org/346593003/diff/1/include/core/SkImageInfo.h#n...
include/core/SkImageInfo.h:123: *  Return true if alphaType is supported by
colorType. If there is a canonical
On 2014/06/18 17:45:43, scroggo wrote:
> Let me know if you think there is a better way to express this. It appears we
> only return false if someone paired kIgnore_SkAlphaType (which may be going
> away, <span id="abbrex-spnAbbr_106764" class="abbrex-Abbr abbrex-Abbr_IIUC
abbrex-AbbrUnknown abbrex-AbbrUnknownVisible">IIUC</span>?) with a valid
SkColorType, or if they used an invalid SkColorType.

Good question. It would be prettier if this guy just returned a (new) alphatype.
For now leave it this way I guess, but we should keep our eyes open for the
chance to change it.

https://codereview.chromium.org/346593003/diff/1/include/core/SkImageInfo.h#n...
include/core/SkImageInfo.h:126: bool SkValidateAlphaType(SkColorType colorType,
SkAlphaType alphaType,
Wonder if the the name should start with colortype or alphatype, as the others
do...

SkColorTypeValidateAlphaType(ct, at, *at) ?

[scroggo, 2014-06-30 22:03:59]

https://codereview.chromium.org/346593003/diff/1/include/core/SkImageInfo.h
File include/core/SkImageInfo.h (right):

https://codereview.chromium.org/346593003/diff/1/include/core/SkImageInfo.h#n...
include/core/SkImageInfo.h:126: bool SkValidateAlphaType(SkColorType colorType,
SkAlphaType alphaType,
On 2014/06/18 17:58:20, reed1 wrote:
> Wonder if the the name should start with colortype or alphatype, as the others
> do...
> 
> SkColorTypeValidateAlphaType(ct, at, *at) ?

Done.

[reed1, 2014-07-01 13:30:36]

nit: CL comment says SkValidateAlphaType, but I think the name is
SkColorTypeValidateAlphaType.

[reed1, 2014-07-01 13:30:44]

lgtm

[scroggo, 2014-07-01 13:36:50]

On 2014/07/01 13:30:36, reed1 wrote:
> nit: CL comment says SkValidateAlphaType, but I think the name is
> SkColorTypeValidateAlphaType.

Done.

[scroggo, 2014-07-01 13:36:53]

The CQ bit was checked by scroggo@google.com

[commit-bot: I haz the power, 2014-07-01 13:37:07]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/scroggo@google.com/346593003/40001

[commit-bot: I haz the power, 2014-07-01 14:08:26]

Change committed as 2fd0d14b9be34a7a945942733c3516d97d07f516