Add test for paint underinvalidation fix with animated transform overflow.

third_party/WebKit/Source/web/tests/sim/SimTest.h

Index: third_party/WebKit/Source/web/tests/sim/SimTest.h
diff --git a/third_party/WebKit/Source/web/tests/sim/SimTest.h b/third_party/WebKit/Source/web/tests/sim/SimTest.h
index d3a84a71caccb1154edd6b2e7e1d5f23ae844bd3..acd15390557304575ac8f3988a961dfbf098047b 100644
--- a/third_party/WebKit/Source/web/tests/sim/SimTest.h
+++ b/third_party/WebKit/Source/web/tests/sim/SimTest.h
@@ -14,14 +14,16 @@
 
 namespace blink {
 
-class WebViewImpl;
-class WebLocalFrameImpl;
 class Document;
 class LocalDOMWindow;
+class WebLocalFrameImpl;
+class WebSettings;
+class WebViewImpl;
 
 class SimTest : public ::testing::Test {
  protected:
   SimTest();
+  SimTest(void (*updateSettingsFunc)(WebSettings*));
   ~SimTest() override;
 
   void loadURL(const String& url);