inline very common intersect+rect_rgn

include/core/SkRegion.h

Index: include/core/SkRegion.h
diff --git a/include/core/SkRegion.h b/include/core/SkRegion.h
index eb0f1367aba4a6b14bca770525bda848bcbbe9c9..a0f0e4ad3c6809dbd562894ea4ed3b754c38fe05 100644
--- a/include/core/SkRegion.h
+++ b/include/core/SkRegion.h
@@ -255,7 +255,15 @@ public:
      *  specified rectangle: this = (this op rect).
      *  Return true if the resulting region is non-empty.
      */
-    bool op(const SkIRect& rect, Op op) { return this->op(*this, rect, op); }
+    bool op(const SkIRect& rect, Op op) {
+        if (this->isRect() && kIntersect_Op == op) {
+            if (!fBounds.intersect(rect)) {
+                return this->setEmpty();
+            }
+            return true;
+        }
+        return this->op(*this, rect, op);
+    }
 
     /**
      *  Set this region to the result of applying the Op to this region and the