change clip-bounds getters to always return the rect
(actually fixes undefined result in getClipBounds)

future CLs
- update all callers to new apis
- move/rename virtuals

BUG=skia:

DOCS_PREVIEW= https://skia.org/?cl=7400

Change-Id: I45b93014e915c0d1c36d97d948c9ac8931f23258
Reviewed-on: https://skia-review.googlesource.com/7400
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Cary Clark <caryclark@google.com>
Commit-Queue: Mike Reed <reed@google.com>
diff --git a/gm/imageblurtiled.cpp b/gm/imageblurtiled.cpp
index 415fa73..bf5d3d1 100644
--- a/gm/imageblurtiled.cpp
+++ b/gm/imageblurtiled.cpp
@@ -33,10 +33,7 @@
         SkPaint paint;
         paint.setImageFilter(SkBlurImageFilter::Make(fSigmaX, fSigmaY, nullptr));
         const SkScalar tileSize = SkIntToScalar(128);
-        SkRect bounds;
-        if (!canvas->getClipBounds(&bounds)) {
-            bounds.setEmpty();
-        }
+        SkRect bounds = canvas->getLocalClipBounds();
         for (SkScalar y = bounds.top(); y < bounds.bottom(); y += tileSize) {
             for (SkScalar x = bounds.left(); x < bounds.right(); x += tileSize) {
                 canvas->save();