Make filter tool actually filter the read in SkPicture

This only implements a trivial filter for empty translates and scales but sets up the framework for more ambitious filtering.

[DerekS, 2012-10-24 18:24:02]

lgtm with a couple of changes

https://codereview.appspot.com/6765046/diff/1/include/core/SkPicture.h
File include/core/SkPicture.h (right):

https://codereview.appspot.com/6765046/diff/1/include/core/SkPicture.h#newcod...
include/core/SkPicture.h:151: SkPictureRecord* fRecord;
comment why this is protected. Something about subclasses providing their own
recorder.

https://codereview.appspot.com/6765046/diff/1/tools/filtermain.cpp
File tools/filtermain.cpp (right):

https://codereview.appspot.com/6765046/diff/1/tools/filtermain.cpp#newcode33
tools/filtermain.cpp:33: , fTotScales(0) {
small nit that is more of a preference so feel free to change it or not.

fTransSkipped
fTransTotal

is easier for me to read as it is consistent in that keeps the subject before
the noun in both cases.  Same goes for scale.

https://codereview.appspot.com/6765046/diff/1/tools/filtermain.cpp#newcode103
tools/filtermain.cpp:103: protected:
remove

[robertphillips, 2012-10-24 19:31:02]

committed as r6080

https://codereview.appspot.com/6765046/diff/1/include/core/SkPicture.h
File include/core/SkPicture.h (right):

https://codereview.appspot.com/6765046/diff/1/include/core/SkPicture.h#newcod...
include/core/SkPicture.h:151: SkPictureRecord* fRecord;
On 2012/10/24 18:24:02, DerekS wrote:
> comment why this is protected. Something about subclasses providing their own
> recorder.

Done.

https://codereview.appspot.com/6765046/diff/1/tools/filtermain.cpp
File tools/filtermain.cpp (right):

https://codereview.appspot.com/6765046/diff/1/tools/filtermain.cpp#newcode33
tools/filtermain.cpp:33: , fTotScales(0) {
On 2012/10/24 18:24:02, DerekS wrote:
> small nit that is more of a preference so feel free to change it or not.
> 
> fTransSkipped
> fTransTotal
> 
> is easier for me to read as it is consistent in that keeps the subject before
> the noun in both cases.  Same goes for scale.

Done.

https://codereview.appspot.com/6765046/diff/1/tools/filtermain.cpp#newcode103
tools/filtermain.cpp:103: protected:
On 2012/10/24 18:24:02, DerekS wrote:
> remove

Done.

[robertphillips, 2012-10-24 19:51:00]

For our captured skp files, all of the scales and 50% of the translates
(201/406) are removed by this filter.

[robertphillips, 2012-10-25 13:37:38]

The filtering of translates and scales (predictably) has a negligible effect on
rendering performance.