Record box shadow as main thread scrolling reasons

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

Index: third_party/WebKit/Source/web/tests/ScrollingCoordinatorTest.cpp
diff --git a/third_party/WebKit/Source/web/tests/ScrollingCoordinatorTest.cpp b/third_party/WebKit/Source/web/tests/ScrollingCoordinatorTest.cpp
index b63f40506c09166436649eeee8c49008228350e3..9c3eca1630e4214be0710e08057f77355d844074 100644
--- a/third_party/WebKit/Source/web/tests/ScrollingCoordinatorTest.cpp
+++ b/third_party/WebKit/Source/web/tests/ScrollingCoordinatorTest.cpp
@@ -1037,7 +1037,11 @@ class StyleRelatedMainThreadScrollingReasonTest
   static const uint32_t m_LCDTextRelatedReasons =
       MainThreadScrollingReason::kHasOpacityAndLCDText |
       MainThreadScrollingReason::kHasTransformAndLCDText |
-      MainThreadScrollingReason::kBackgroundNotOpaqueInRectAndLCDText;
+      MainThreadScrollingReason::kBackgroundNotOpaqueInRectAndLCDText |
+      MainThreadScrollingReason::kHasBoxShadowAndLCDText |
+      MainThreadScrollingReason::kHasTranslucentBorderAndLCDText;
+  static const uint32_t m_OpaqueScrollersRelatedReasons =
+      MainThreadScrollingReason::kHasTranslucentBorderAndLCDText;
 
  protected:
   StyleRelatedMainThreadScrollingReasonTest() {
@@ -1089,6 +1093,12 @@ class StyleRelatedMainThreadScrollingReasonTest
       forceFullCompositingUpdate();
       ASSERT_FALSE(frameView->mainThreadScrollingReasons());
     }
+    if ((reason & m_OpaqueScrollersRelatedReasons) &&
+        !(reason & ~m_OpaqueScrollersRelatedReasons)) {
+      RuntimeEnabledFeatures::setCompositeOpaqueScrollersEnabled(true);
+      forceFullCompositingUpdate();
+      ASSERT_FALSE(frameView->mainThreadScrollingReasons());
+    }
   }
 };
 
@@ -1154,4 +1164,20 @@ TEST_F(StyleRelatedMainThreadScrollingReasonTest, LCDTextEnabledTest) {
                 MainThreadScrollingReason::kHasBorderRadius);
 }
 
+TEST_F(StyleRelatedMainThreadScrollingReasonTest, BoxShadowTest) {
+  testStyle("box-shadow", MainThreadScrollingReason::kHasBoxShadowAndLCDText);
+}
+
+TEST_F(StyleRelatedMainThreadScrollingReasonTest, TranslucentBorderTest) {
+  RuntimeEnabledFeatures::setCompositeOpaqueScrollersEnabled(false);
+  testStyle("translucent-border",
+            MainThreadScrollingReason::kHasTranslucentBorderAndLCDText);
+}
+
+TEST_F(StyleRelatedMainThreadScrollingReasonTest, OpaqueScrollersEnabledTest) {
+  testStyle("translucent-border border-radius",
+            MainThreadScrollingReason::kHasOpacityAndLCDText |
+                MainThreadScrollingReason::kHasBorderRadius);
+}
+
 }  // namespace blink