context.addHitRegion should return if the DOMException occurs.

Source/core/html/canvas/CanvasRenderingContext2D.cpp

Index: Source/core/html/canvas/CanvasRenderingContext2D.cpp
diff --git a/Source/core/html/canvas/CanvasRenderingContext2D.cpp b/Source/core/html/canvas/CanvasRenderingContext2D.cpp
index de7a380d673a8cd3a323a79cf499aaecd6e609af..d9ae2a31615f5c3f2407cf01fc68e8f9f5a2e094 100644
--- a/Source/core/html/canvas/CanvasRenderingContext2D.cpp
+++ b/Source/core/html/canvas/CanvasRenderingContext2D.cpp
@@ -2393,6 +2393,7 @@ void CanvasRenderingContext2D::addHitRegion(const Dictionary& options, Exception
         // However, we have no way to get the region from canvas state stack by now.
         // See http://crbug.com/387057
         exceptionState.throwDOMException(NotSupportedError, "The specified path has no pixels.");
+        return;
     }
 
     passOptions.path = specifiedPath;