Initial picture shader implementation

This CL adds an SkPictureShader class to support SkPicture-based
patterns.

The implementation renders the picture into an SkBitmap tile and then
delegates to SkBitmapProcShader for the actual operation.

R=bsalomon@google.com, reed@google.com, robertphillips@google.com

Committed: http://code.google.com/p/skia/source/detail?r=14085

Author: fmalita@chromium.org

Review URL: https://codereview.chromium.org/221923007

git-svn-id: http://skia.googlecode.com/svn/trunk@14092 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gyp/core.gypi b/gyp/core.gypi
index df026a4..4a923d7 100644
--- a/gyp/core.gypi
+++ b/gyp/core.gypi
@@ -134,6 +134,8 @@
         '<(skia_src_path)/core/SkPicturePlayback.h',
         '<(skia_src_path)/core/SkPictureRecord.cpp',
         '<(skia_src_path)/core/SkPictureRecord.h',
+        '<(skia_src_path)/core/SkPictureShader.cpp',
+        '<(skia_src_path)/core/SkPictureShader.h',
         '<(skia_src_path)/core/SkPictureStateTree.cpp',
         '<(skia_src_path)/core/SkPictureStateTree.h',
         '<(skia_src_path)/core/SkPixelRef.cpp',