Record box shadow as main thread scrolling reasons

third_party/WebKit/Source/web/tests/ScrollingCoordinatorTest.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 1019 matching lines @@
   ASSERT_FALSE(
       webScrollLayer->mainThreadScrollingReasons() &
       MainThreadScrollingReason::kHasNonLayerViewportConstrainedObjects);
 }
 
 class StyleRelatedMainThreadScrollingReasonTest
     : public ScrollingCoordinatorTest {
   static const uint32_t m_LCDTextRelatedReasons =
       MainThreadScrollingReason::kHasOpacityAndLCDText |
       MainThreadScrollingReason::kHasTransformAndLCDText |
-      MainThreadScrollingReason::kBackgroundNotOpaqueInRectAndLCDText;
+      MainThreadScrollingReason::kBackgroundNotOpaqueInRectAndLCDText |
+      MainThreadScrollingReason::kHasBoxShadowAndLCDText;
 
  protected:
   StyleRelatedMainThreadScrollingReasonTest() {
     registerMockedHttpURLLoad("two_scrollable_area.html");
     navigateTo(m_baseURL + "two_scrollable_area.html");
   }
   void testStyle(const std::string& target, const uint32_t reason) {
     webViewImpl()->settings()->setPreferCompositingToLCDTextEnabled(false);
     Document* document = frame()->document();
     Element* container = document->getElementById("scroller1");
@@ skipping 96 matching lines @@
   forceFullCompositingUpdate();
   ASSERT_FALSE(frameView->mainThreadScrollingReasons() & reason);
 }
 
 TEST_F(StyleRelatedMainThreadScrollingReasonTest, LCDTextEnabledTest) {
   testStyle("transparent border-radius",
             MainThreadScrollingReason::kHasOpacityAndLCDText |
                 MainThreadScrollingReason::kHasBorderRadius);
 }
 
+TEST_F(StyleRelatedMainThreadScrollingReasonTest, BoxShadowTest) {
+  testStyle("box-shadow", MainThreadScrollingReason::kHasBoxShadowAndLCDText);
+}
+
 }  // namespace blink