Replace filter outsets with bounds mapping in Blink.

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

Index: third_party/WebKit/Source/platform/graphics/filters/FilterEffect.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/filters/FilterEffect.cpp b/third_party/WebKit/Source/platform/graphics/filters/FilterEffect.cpp
index 3c4448004c871e75ab4517c96f11987c6f3e9f5c..a533ca05316c0627b22fca8297fa4ab8bb4b2840 100644
--- a/third_party/WebKit/Source/platform/graphics/filters/FilterEffect.cpp
+++ b/third_party/WebKit/Source/platform/graphics/filters/FilterEffect.cpp
@@ -85,16 +85,20 @@ FloatRect FilterEffect::determineAbsolutePaintRect(const FloatRect& originalRequ
     return inputUnion;
 }
 
-FloatRect FilterEffect::mapRectRecursive(const FloatRect& rect) const
+FloatRect FilterEffect::mapRectRecursive(const FloatRect& rect, bool forward) const
 {
-    FloatRect result;
-    if (m_inputEffects.size() > 0) {
-        result = m_inputEffects.at(0)->mapRectRecursive(rect);
+    auto mapInputs = [this](const FloatRect& rect, bool forward)
+    {
+        if (!m_inputEffects.size())
+            return rect;
+        FloatRect result = m_inputEffects.at(0)->mapRectRecursive(rect, forward);
         for (unsigned i = 1; i < m_inputEffects.size(); ++i)
-            result.unite(m_inputEffects.at(i)->mapRectRecursive(rect));
-    } else
-        result = rect;
-    return mapRect(result);
+            result.unite(m_inputEffects.at(i)->mapRectRecursive(rect, forward));
+        return result;
+    };
+    return forward
+        ? mapRect(mapInputs(rect, forward), forward)
+        : mapInputs(mapRect(rect, forward), forward);
 }
 
 FilterEffect* FilterEffect::inputEffect(unsigned number) const