OverscrollGlow for mainThread-{BLINK CHANGES}

Source/web/tests/WebFrameTest.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 7255 matching lines @@
     EXPECT_TRUE(webFrameClient.messages.empty());
     ASSERT_EQ(2u, popupWebFrameClient.messages.size());
     EXPECT_TRUE(std::string::npos != popupWebFrameClient.messages[1].text.utf8().find("Blocked a frame"));
 
     // Manually reset to break WebViewHelpers' dependencies on the stack
     // allocated WebFrameClients.
     webViewHelper.reset();
     popupWebViewHelper.reset();
 }
 
+TEST_F(WebFrameTest, OverscrollGlowAnimation)
+{
+    UseMockScrollbarSettings mockScrollbarSettings;
+    registerMockedHttpURLLoad("mainthread_scrolling.html");
+
+    FixedLayoutTestWebViewClient client;
+    client.m_screenInfo.deviceScaleFactor = 1;
+    int viewportWidth = 640;
+    int viewportHeight = 480;
+
+    FrameTestHelpers::WebViewHelper webViewHelper;
+
+    webViewHelper.initializeAndLoad(m_baseURL + "mainthread_scrolling.html", true, 0, &client, configureAndroid);
+    // set view height to zero so that if the height of the view is not
+    // successfully updated during later resizes touch events will fail
+    // (as in not hit content included in the view)
+    webViewHelper.webView()->resize(WebSize(viewportWidth, 0));
+    webViewHelper.webView()->layout();
+

[majidvp, 2015/05/07 16:35:30]

Why do you need this resize here?

+    webViewHelper.webView()->settings()->setForceZeroLayoutHeight(true);
+    webViewHelper.webView()->resize(WebSize(viewportWidth, viewportHeight));
+

[majidvp, 2015/05/07 16:35:30]

Again resize does not make sense to me.

+    IntPoint hitPoint = IntPoint(5, 5);
+
+    PlatformGestureEvent gestureEventSB(PlatformEvent::Type::GestureScrollBegin, hitPoint, hitPoint, IntSize(0, 0), 0, false, false, false, false);
+    webViewHelper.webViewImpl()->mainFrameImpl()->frame()->eventHandler().handleGestureEvent(gestureEventSB);

[majidvp, 2015/05/07 16:35:30]

I think it is better to have webView handle the gesture instead of passing it
directly to main frame event handler. That allows you to test scrolls that
happen inside iframes as well.

See |TopControlsTest.cpp| for example of how you can do that.

+
+    PlatformGestureEvent gestureEventSU1(PlatformEvent::Type::GestureScrollUpdate, hitPoint, hitPoint, IntSize(0, 0), 0, false, false, false, false);
+    gestureEventSU1.setScrollGestureData(0, -13, 0, 0, false, false);
+    webViewHelper.webViewImpl()->mainFrameImpl()->frame()->eventHandler().handleGestureEvent(gestureEventSU1);
+    FloatSize unUsedDelta = webViewHelper.webViewImpl()->mainFrameImpl()->frame()->eventHandler().unusedDeltaForTesting();
+    FloatSize accumulatedRootOverscroll = webViewHelper.webViewImpl()->mainFrameImpl()->frame()->eventHandler().accumulatedRootOverscrollForTesting();
+    EXPECT_EQ(0, unUsedDelta.width());
+    EXPECT_EQ(-13, unUsedDelta.height());
+    EXPECT_EQ(0, accumulatedRootOverscroll.width());
+    EXPECT_EQ(-13, accumulatedRootOverscroll.height());
+
+    PlatformGestureEvent gestureEventSU2(PlatformEvent::Type::GestureScrollUpdate, hitPoint, hitPoint, IntSize(0, 0), 0, false, false, false, false);
+    gestureEventSU2.setScrollGestureData(0, -13, 0, 0, false, false);
+    webViewHelper.webViewImpl()->mainFrameImpl()->frame()->eventHandler().handleGestureEvent(gestureEventSU2);
+    unUsedDelta = webViewHelper.webViewImpl()->mainFrameImpl()->frame()->eventHandler().unusedDeltaForTesting();
+    accumulatedRootOverscroll = webViewHelper.webViewImpl()->mainFrameImpl()->frame()->eventHandler().accumulatedRootOverscrollForTesting();
+    EXPECT_EQ(0, unUsedDelta.width());
+    EXPECT_EQ(-13, unUsedDelta.height());
+    EXPECT_EQ(0, accumulatedRootOverscroll.width());
+    EXPECT_EQ(-26, accumulatedRootOverscroll.height());

[majidvp, 2015/05/07 16:35:30]

This tests the simple case where we have overscroll. It does not test any of the
following:
- accumulated over scroll reset logic
   - within a single scroll gesture
   - between different scroll gesture

- Scroll delta being correctly calculated for both axis
- Scrolling inner scrollers
- Scrolling iframes
- Impact of scale on overscroll delta

In general you should try to match any of the overscroll related tests in CC
that makes sense here. Search 'overscroll' in |layer_tree_host_impl_unittest.cc|
to see them.

Also I think it is best to move all overscroll tests into their own Test class. 

+
+    PlatformGestureEvent gestureEventSE(PlatformEvent::Type::GestureScrollEnd, hitPoint, hitPoint, IntSize(0, 0), 0, false, false, false, false);
+    webViewHelper.webViewImpl()->mainFrameImpl()->frame()->eventHandler().handleGestureEvent(gestureEventSE);
+}
+
 } // namespace blink