Switch SkBlurImageFilter over to new onFilterImage interface

src/core/SkSpecialImage.cpp

Index: src/core/SkSpecialImage.cpp
diff --git a/src/core/SkSpecialImage.cpp b/src/core/SkSpecialImage.cpp
index dfbde75dc7eea30813401f1e45ecde11893d48a8..f49f22859ac4fe4138eaf8a40fbf35841b80fd76 100644
--- a/src/core/SkSpecialImage.cpp
+++ b/src/core/SkSpecialImage.cpp
@@ -325,10 +325,15 @@ public:
 
     bool onPeekPixels(SkPixmap* pixmap) const override {
         const SkImageInfo info = fBitmap.info();
-        if ((kUnknown_SkColorType == info.colorType()) || !fBitmap.getPixels()) {
+
+        if (kUnknown_SkColorType == info.colorType()) {
             return false;
         }
 
+        if (!fBitmap.peekPixels(pixmap)) {
+            fBitmap.lockPixels();
+        }
+
         return fBitmap.peekPixels(pixmap);
     }