Fixing deferred canvas bug caused by SkTwoPointConicalGradient declaring itself as opaque.

BUG=https://code.google.com/p/chromium/issues/detail?id=222140
TEST=DeferredCanvas unit test + DRT with --enable-deferred-2d-canvas

Author: junov@chromium.org

Reviewed By: bsalomon@chromium.org

Review URL: https://chromiumcodereview.appspot.com/12879005

git-svn-id: http://skia.googlecode.com/svn/trunk@8247 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/effects/gradients/SkTwoPointConicalGradient.h b/src/effects/gradients/SkTwoPointConicalGradient.h
index e02c390..0807ae3 100644
--- a/src/effects/gradients/SkTwoPointConicalGradient.h
+++ b/src/effects/gradients/SkTwoPointConicalGradient.h
@@ -62,6 +62,7 @@
                                  TileMode* xy) const;
     virtual SkShader::GradientType asAGradient(GradientInfo* info) const  SK_OVERRIDE;
     virtual GrEffectRef* asNewEffect(GrContext* context, const SkPaint& paint) const SK_OVERRIDE;
+    virtual bool isOpaque() const SK_OVERRIDE;
 
     SkScalar getCenterX1() const { return SkPoint::Distance(fCenter1, fCenter2); }
     SkScalar getStartRadius() const { return fRadius1; }