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/SampleStrokePath.cpp b/samplecode/SampleStrokePath.cpp
index ce6a010..4526512 100644
--- a/samplecode/SampleStrokePath.cpp
+++ b/samplecode/SampleStrokePath.cpp
@@ -160,11 +160,11 @@
             paint.setColor(SK_ColorWHITE);
             canvas->translate(10, 30);
 
-            static const SkBlurMaskFilter::BlurStyle gStyle[] = {
-                SkBlurMaskFilter::kNormal_BlurStyle,
-                SkBlurMaskFilter::kInner_BlurStyle,
-                SkBlurMaskFilter::kOuter_BlurStyle,
-                SkBlurMaskFilter::kSolid_BlurStyle,
+            static const SkBlurStyle gStyle[] = {
+                kNormal_SkBlurStyle,
+                kInner_SkBlurStyle,
+                kOuter_SkBlurStyle,
+                kSolid_SkBlurStyle,
             };
             for (int x = 0; x < 5; x++) {
                 SkMaskFilter* mf;