Add canFilterMaskGPU & filterMaskGPU to SkMaskFilter

tests/BlurTest.cpp

Index: tests/BlurTest.cpp
===================================================================
--- tests/BlurTest.cpp	(revision 9883)
+++ tests/BlurTest.cpp	(working copy)
@@ -105,18 +105,6 @@
             SkMaskFilter* filter;
             filter = SkBlurMaskFilter::Create(radius, blurStyle, flags);
 
-            SkMaskFilter::BlurInfo info;
-            sk_bzero(&info, sizeof(info));
-            SkMaskFilter::BlurType type = filter->asABlur(&info);
-
-            REPORTER_ASSERT(reporter, type ==
-                static_cast<SkMaskFilter::BlurType>(style + 1));
-            REPORTER_ASSERT(reporter, info.fRadius == radius);
-            REPORTER_ASSERT(reporter, info.fIgnoreTransform ==
-                SkToBool(flags & SkBlurMaskFilter::kIgnoreTransform_BlurFlag));
-            REPORTER_ASSERT(reporter, info.fHighQuality ==
-                SkToBool(flags & SkBlurMaskFilter::kHighQuality_BlurFlag));
-
             paint.setMaskFilter(filter);
             filter->unref();