[PDF] Fix setting of existing clip for layers.

[PDF] Fix setting of existing clip for layers.

The current approach of setting the existing clip just before drawing a layer into a device doesn't work.  SkDevice::clear() uses existing clip before that and if we need to put the content in a transparency group (i.e. for SrcIn xfermode), we need a valid existing clip.  Instead, change the factory to use a special constructor when creating a layer device.

Committed: http://code.google.com/p/skia/source/detail?r=1270

[Steve VanDeBogart, 2011-05-06 17:20:30]

I could just add this to http://codereview.appspot.com/4459041/ instead, if you
prefer.

[Chris Guillory, 2011-05-06 18:59:35]

LGTM.

http://codereview.appspot.com/4495041/diff/1/src/pdf/SkPDFDevice.cpp
File src/pdf/SkPDFDevice.cpp (right):

http://codereview.appspot.com/4495041/diff/1/src/pdf/SkPDFDevice.cpp#newcode447
src/pdf/SkPDFDevice.cpp:447: // needs to be done once, we we don't do it when
layering.
Nit: we we -> we

[Steve VanDeBogart, 2011-05-06 21:39:39]

http://codereview.appspot.com/4495041/diff/1/src/pdf/SkPDFDevice.cpp
File src/pdf/SkPDFDevice.cpp (right):

http://codereview.appspot.com/4495041/diff/1/src/pdf/SkPDFDevice.cpp#newcode447
src/pdf/SkPDFDevice.cpp:447: // needs to be done once, we we don't do it when
layering.
On 2011/05/06 18:59:35, Chris Guillory wrote:
> Nit: we we -> we

Done.

[Steve VanDeBogart, 2011-05-06 21:41:55]

+reed In case he has any comment on this.

Currently, this is a bit ugly, but if we kill factories, it'll be much better,
as we'll ask the parent layer to create the device for the new layer and it
knows what the existing clip is.