Merge perspective feature for PDF.

From Skia's repo:

http://code.google.com/p/skia/source/detail?r=11751
Add SkPDFDeviceFlatenner which extends SkPDFDevice to add support
to flatten the path and the text when we have perspective. prepare
to deprecate SkPDFDevice constructor, and route gm and render_pdfs
to use SkDocument::Create pdf interface instead. - controlled by a
flag add comments where we are supposed to flatten other features
(paint, shaders, ... )

https://code.google.com/p/skia/source/detail?r=11822
Implement perspective for bitmaps in pdf.

https://code.google.com/p/skia/source/detail?r=11937
PDF: support perspective in simple shaders. (this version does not
work well with tilling)

BUG:11384071

Change-Id: I48ea88d231231215349f155d972c6b9e1e127c71
15 files changed