Add base effect for gpu 2pt conical gradients

This is in preparation to add more "sub-effects" for the various fast path cases for 2 pt conical gradients

BUG=skia:
R=jvanverth@google.com, robertphillips@google.com, bsalomon@google.com

Author: egdaniel@google.com

Review URL: https://codereview.chromium.org/224083002

git-svn-id: http://skia.googlecode.com/svn/trunk@14059 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/effects/gradients/SkTwoPointConicalGradient.h b/src/effects/gradients/SkTwoPointConicalGradient.h
index 71ba57f..041f8b8 100644
--- a/src/effects/gradients/SkTwoPointConicalGradient.h
+++ b/src/effects/gradients/SkTwoPointConicalGradient.h
@@ -65,6 +65,9 @@
     SkScalar getCenterX1() const { return SkPoint::Distance(fCenter1, fCenter2); }
     SkScalar getStartRadius() const { return fRadius1; }
     SkScalar getDiffRadius() const { return fRadius2 - fRadius1; }
+    const SkPoint& getStartCenter() const { return fCenter1; }
+    const SkPoint& getEndCenter() const { return fCenter2; }
+    SkScalar getEndRadius() const { return fRadius2; }
 
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTwoPointConicalGradient)