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 eae62086b723a87d8bac51caeb859d0c8cacd584..4bb809848262d190b90b8995543f32e3101a5570 100644
--- a/third_party/WebKit/Source/web/tests/VisualViewportTest.cpp
+++ b/third_party/WebKit/Source/web/tests/VisualViewportTest.cpp
@@ -305,6 +305,48 @@ TEST_P(VisualViewportTest, TestResizeAtFullyScrolledPreservesViewportLocation) {
       frameView.getScrollableArea()->visibleContentRect().location());
 }
 
+// Test the main frame scrollbars take visual viewport into account.
+TEST_P(VisualViewportTest, VerifyScrollbarBehavior) {
+  // TODO(ymalik): With root layer scrolling enabled, the scroller returned
+  // by FrameView is PaintLayerScrollableArea. PLSA doesn't know about the
+  // visual viewport and thus, scrollbars aren't added when we zoom in.
+  if (RuntimeEnabledFeatures::rootLayerScrollingEnabled())

[bokan, 2016/11/03 19:59:59]

Run the test but change the expectations below based on bool rootLayerScrolls =
GetParam().

[ymalik, 2016/11/04 18:54:18]

Good tip. Done.

+    return;
+
+  initializeWithDesktopSettings();
+
+  registerMockedHttpURLLoad("200-by-800-viewport.html");
+  navigateTo(m_baseURL + "200-by-800-viewport.html");
+
+  webViewImpl()->resize(IntSize(300, 200));
+
+  ScrollableArea* scroller = frame()->view()->getScrollableArea();
+
+  // Initially, there is no horizontal scrollbar since the content fits.
+  EXPECT_FALSE(scroller->horizontalScrollbar());
+  EXPECT_TRUE(scroller->verticalScrollbar());
+
+  // Scroll layout viewport.
+  webViewImpl()->mainFrame()->setScrollOffset(WebSize(0, 200));
+  EXPECT_SIZE_EQ(ScrollOffset(0, 200), scroller->scrollOffset());
+
+  webViewImpl()->setPageScaleFactor(2.0);
+
+  // Pinch-zooming should add horizontal scrollbar.
+  EXPECT_TRUE(scroller->horizontalScrollbar());
+  EXPECT_TRUE(scroller->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, scroller->horizontalScrollbar()->currentPos());
+  EXPECT_FLOAT_EQ(300, scroller->verticalScrollbar()->currentPos());
+}
+
 // Test that the VisualViewport works as expected in case of a scaled
 // and scrolled viewport - scroll down.
 TEST_P(VisualViewportTest, TestResizeAfterVerticalScroll) {