Add support for rotating / scaling / translating gpu cached distance field textblobs

Add support for rotating / scaling / translating gpu cached distance field textblobs

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/64c99cc90e678feba473d38db420d31883cc53e6

[joshualitt, 2015-04-20 20:17:39]

joshualitt@google.com changed reviewers:
+ bsalomon@google.com, joshualitt@google.com, jvanverth@google.com,
robertphillips@google.com

[joshualitt, 2015-04-20 20:17:40]

ptal

[jvanverth1, 2015-04-21 15:29:48]

LGTM + comments

https://codereview.chromium.org/1092283002/diff/60001/src/gpu/GrAtlasTextCont...
File src/gpu/GrAtlasTextContext.cpp (right):

https://codereview.chromium.org/1092283002/diff/60001/src/gpu/GrAtlasTextCont...
src/gpu/GrAtlasTextContext.cpp:629: // minMaxScale to make regeneration
decisions
A little more detail in a comment on how this works would be useful. I think I
worked it out on paper, but it'd be nice to just read it.

https://codereview.chromium.org/1092283002/diff/60001/src/gpu/GrAtlasTextCont...
File src/gpu/GrAtlasTextContext.h (right):

https://codereview.chromium.org/1092283002/diff/60001/src/gpu/GrAtlasTextCont...
src/gpu/GrAtlasTextContext.h:237: // We can regenerate distance field text, but
only if the new viewmatrix would not result in
s/regenerate/reuse/ ?

[joshualitt, 2015-04-21 16:06:04]

The CQ bit was checked by joshualitt@google.com

[joshualitt, 2015-04-21 16:06:04]

The patchset sent to the CQ was uploaded after l-g-t-m from jvanverth@google.com
Link to the patchset: https://codereview.chromium.org/1092283002/#ps80001
(title: "adding comment")

[commit-bot: I haz the power, 2015-04-21 16:06:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1092283002/80001

[joshualitt, 2015-04-21 16:07:11]

The CQ bit was unchecked by joshualitt@google.com

[joshualitt, 2015-04-21 16:38:46]

The CQ bit was checked by joshualitt@google.com

[commit-bot: I haz the power, 2015-04-21 16:38:58]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1092283002/80001

[commit-bot: I haz the power, 2015-04-21 16:43:07]

Committed patchset #5 (id:80001) as
https://skia.googlesource.com/skia/+/64c99cc90e678feba473d38db420d31883cc53e6