make set3DMask virtual, so we can safely notify the shadercontext

make set3DMask virtual, so we can safely notify the shadercontext

also boost preallocated storage to account for this combo of bitmapshader + emboss + colorfilter

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/cc0e3110bde60201882a2c512a5cdd73c838f351

[reed1, 2014-09-10 15:13:37]

reed@google.com changed reviewers:
+ djsollen@google.com

[reed1, 2014-09-10 15:13:38]

will make a real gm before submitting

[djsollen, 2014-09-10 17:01:07]

lg pending GM

[reed1, 2014-09-10 17:11:04]

The CQ bit was checked by reed@google.com

[reed1, 2014-09-10 17:11:51]

ptal

[commit-bot: I haz the power, 2014-09-10 17:11:52]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/reed@google.com/563563002/20001

[commit-bot: I haz the power, 2014-09-10 17:11:53]

Note for Reviewers:
The CQ is waiting for an approval.
If you believe that the CL is not ready yet, or if you would like to L-G-T-M
with comments then please uncheck the CQ checkbox.

Waiting for LGTM from a valid reviewer till 2014-09-10 23:11 UTC

[djsollen, 2014-09-10 17:12:50]

lgtm

[commit-bot: I haz the power, 2014-09-10 17:20:29]

Committed patchset #2 (id:20001) as cc0e3110bde60201882a2c512a5cdd73c838f351