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 418e6480cd5f46389c1a47420f68a29dbdcb0223..68af0e71715fc25b22982881f3a5c2d0e9b4041e 100644
--- a/third_party/WebKit/Source/web/tests/VisualViewportTest.cpp
+++ b/third_party/WebKit/Source/web/tests/VisualViewportTest.cpp
@@ -307,6 +307,54 @@ 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

[skobes, 2016/11/09 23:18:25]

If the test doesn't work with RLS, it shouldn't be parameterized.  Don't fake it
by checking the RLS setting.

[bokan, 2016/11/10 15:16:57]

I asked for this. The test should eventually work with RLS but doesn't yet.
Checking for behavior with RLS will make sure we remember to update this when we
fix RLS to work here as well (since the test will "break" if RLS is fixed).

[ymalik, 2016/11/10 17:58:04]

I agree with this. It will increase the chances that this gets fixed when RLS is
enabled by default. @skobes, WDYT?

+  // by FrameView is PaintLayerScrollableArea. PLSA doesn't know about the
+  // visual viewport and thus, scrollbars aren't added when we zoom in.
+  bool rootLayerScrolls = RuntimeEnabledFeatures::rootLayerScrollingEnabled();
+
+  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.
+  if (!rootLayerScrolls)
+    EXPECT_TRUE(scroller->horizontalScrollbar());
+  else
+    EXPECT_FALSE(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.
+  if (!rootLayerScrolls) {
+    EXPECT_FLOAT_EQ(100, scroller->horizontalScrollbar()->currentPos());
+    EXPECT_FLOAT_EQ(300, scroller->verticalScrollbar()->currentPos());
+  } else {
+    EXPECT_FLOAT_EQ(200, scroller->verticalScrollbar()->currentPos());
+  }
+}
+
 // Test that the VisualViewport works as expected in case of a scaled
 // and scrolled viewport - scroll down.
 TEST_P(VisualViewportTest, TestResizeAfterVerticalScroll) {