MainFrame scrollbars should work with RFV instead of FV

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

Index: third_party/WebKit/Source/web/tests/VisualViewportTest.cpp
diff --git a/third_party/WebKit/Source/web/tests/VisualViewportTest.cpp b/third_party/WebKit/Source/web/tests/VisualViewportTest.cpp
index f8ce086869b075e455506b9853c7ba6e9d419296..72c5cf423fa60ff1244cfcf1c0f334da3136bc5d 100644
--- a/third_party/WebKit/Source/web/tests/VisualViewportTest.cpp
+++ b/third_party/WebKit/Source/web/tests/VisualViewportTest.cpp
@@ -275,6 +275,42 @@ TEST_P(ParameterizedVisualViewportTest,
       frameView.getScrollableArea()->visibleContentRect().location());
 }
 
+// Test the main frame scrollbars take visual viewport into account.
+TEST_F(VisualViewportTest, VerifyScrollbarBehavior) {
+  initializeWithDesktopSettings();
+
+  registerMockedHttpURLLoad("200-by-800-viewport.html");
+  navigateTo(m_baseURL + "200-by-800-viewport.html");
+
+  webViewImpl()->resize(IntSize(300, 200));
+
+  // Initially, there is no horizontal scrollbar since the content fits.
+  EXPECT_FALSE(frame()->view()->horizontalScrollbar());
+  EXPECT_TRUE(frame()->view()->verticalScrollbar());
+
+  // Scroll layout viewport.
+  webViewImpl()->mainFrame()->setScrollOffset(WebSize(0, 200));
+  EXPECT_SIZE_EQ(
+      ScrollOffset(0, 200),
+      frame()->view()->layoutViewportScrollableArea()->scrollOffset());
+
+  webViewImpl()->setPageScaleFactor(2.0);
+
+  // Pinch-zooming should add horizontal scrollbar.
+  EXPECT_TRUE(frame()->view()->horizontalScrollbar());
+  EXPECT_TRUE(frame()->view()->verticalScrollbar());
+
+  // Scroll visual viewport.
+  VisualViewport& visualViewport =
+      frame()->page()->frameHost().visualViewport();
+  visualViewport.setLocation(FloatPoint(100, 100));
+  EXPECT_FLOAT_SIZE_EQ(FloatSize(100, 100), visualViewport.scrollOffset());
+
+  // Scrollbar offset should take visual viewport into account.
+  EXPECT_FLOAT_EQ(100, frame()->view()->horizontalScrollbar()->currentPos());
+  EXPECT_FLOAT_EQ(300, frame()->view()->verticalScrollbar()->currentPos());
+}
+
 // Test that the VisualViewport works as expected in case of a scaled
 // and scrolled viewport - scroll down.
 TEST_P(ParameterizedVisualViewportTest, TestResizeAfterVerticalScroll) {