Harmonize FilterEffect::mapRect and mapPaintRect

third_party/WebKit/Source/platform/graphics/filters/SourceGraphic.cpp

Index: third_party/WebKit/Source/platform/graphics/filters/SourceGraphic.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/filters/SourceGraphic.cpp b/third_party/WebKit/Source/platform/graphics/filters/SourceGraphic.cpp
index 2cc974d6e754159c77860a9d820afddb199e7753..6708600d2437a0a0765265691b1fb681753ba0bf 100644
--- a/third_party/WebKit/Source/platform/graphics/filters/SourceGraphic.cpp
+++ b/third_party/WebKit/Source/platform/graphics/filters/SourceGraphic.cpp
@@ -40,9 +40,9 @@ SourceGraphic* SourceGraphic::create(Filter* filter)
     return new SourceGraphic(filter);
 }
 
-FloatRect SourceGraphic::determineAbsolutePaintRect(const FloatRect& requestedRect) const
+FloatRect SourceGraphic::mapInputs(const FloatRect& rect) const
 {
-    return intersection(m_sourceRect, requestedRect);
+    return !m_sourceRect.isEmpty() ? m_sourceRect : rect;
 }
 
 void SourceGraphic::setSourceRect(const IntRect& sourceRect)