move common blur types into central header

BUG=skia:
R=scroggo@google.com, djsollen@google.com

Author: reed@google.com

Review URL: https://codereview.chromium.org/253833002

git-svn-id: http://skia.googlecode.com/svn/trunk@14411 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/samplecode/SampleEffects.cpp b/samplecode/SampleEffects.cpp
index cbefae8..01a63ad 100644
--- a/samplecode/SampleEffects.cpp
+++ b/samplecode/SampleEffects.cpp
@@ -24,7 +24,7 @@
 
 static void paint_proc1(SkPaint* paint) {
     paint->setMaskFilter(SkBlurMaskFilter::Create(
-                                SkBlurMaskFilter::kNormal_BlurStyle,
+                                kNormal_SkBlurStyle,
                                 SkBlurMask::ConvertRadiusToSigma(SkIntToScalar(2))))->unref();
 }