Disable fractional scroll feature by default

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/frame/VisualViewport.h"
 
 #include "core/dom/Document.h"
 #include "core/frame/FrameHost.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
@@ skipping 494 matching lines @@
     EXPECT_FLOAT_RECT_EQ(FloatRect(10, 15, 50, 200), visualViewport.visibleRectInDocument());
 
     // Scroll the layout viewport. Ensure its offset is reflected in visibleRectInDocument().
     FrameView& frameView = *webViewImpl()->mainFrameImpl()->frameView();
     frameView.layoutViewportScrollableArea()->setScrollPosition(DoublePoint(40, 100), ProgrammaticScroll);
     EXPECT_FLOAT_RECT_EQ(FloatRect(50, 115, 50, 200), visualViewport.visibleRectInDocument());
 }
 
 TEST_P(ParameterizedVisualViewportTest, TestFractionalScrollOffsetIsNotOverwritten)
 {
+    bool origFractionalOffsetsEnabled = RuntimeEnabledFeatures::fractionalScrollOffsetsEnabled();
+    RuntimeEnabledFeatures::setFractionalScrollOffsetsEnabled(true);
+
     initializeWithAndroidSettings();
     webViewImpl()->resize(IntSize(200, 250));
 
     registerMockedHttpURLLoad("200-by-800-viewport.html");
     navigateTo(m_baseURL + "200-by-800-viewport.html");
 
     FrameView& frameView = *webViewImpl()->mainFrameImpl()->frameView();
     frameView.layoutViewportScrollableArea()->setScrollPosition(DoublePoint(0, 10.5), ProgrammaticScroll);
     webViewImpl()->applyViewportDeltas(WebFloatSize(), WebFloatSize(10, 20), WebFloatSize(), 1, 0);
 
     EXPECT_EQ(30.5, frameView.layoutViewportScrollableArea()->scrollPositionDouble().y());
+
+    RuntimeEnabledFeatures::setFractionalScrollOffsetsEnabled(origFractionalOffsetsEnabled);
 }
 
 // Test that the viewport's scroll offset is always appropriately bounded such that the
 // visual viewport always stays within the bounds of the main frame.
 TEST_P(ParameterizedVisualViewportTest, TestOffsetClamping)
 {
     initializeWithDesktopSettings();
     webViewImpl()->resize(IntSize(320, 240));
 
     navigateTo("about:blank");
@@ skipping 569 matching lines @@
     Mock::VerifyAndClearExpectations(&mockWebFrameClient);
 
     // Scroll horizontally.
     EXPECT_CALL(mockWebFrameClient, didChangeScrollOffset(_));
     visualViewport.setLocation(FloatPoint(70, 90));
 
     // Reset the old client so destruction can occur naturally.
     webViewImpl()->mainFrameImpl()->setClient(oldClient);
 }
 
-// Tests that calling scroll into view on a visible element doesn cause
+// Tests that calling scroll into view on a visible element doesn't cause
 // a scroll due to a fractional offset. Bug crbug.com/463356.
 TEST_P(ParameterizedVisualViewportTest, ScrollIntoViewFractionalOffset)
 {
     initializeWithAndroidSettings();
 
     webViewImpl()->resize(IntSize(1000, 1000));
 
     registerMockedHttpURLLoad("scroll-into-view.html");
     navigateTo(m_baseURL + "scroll-into-view.html");
 
     FrameView& frameView = *webViewImpl()->mainFrameImpl()->frameView();
     ScrollableArea* layoutViewportScrollableArea = frameView.layoutViewportScrollableArea();
     VisualViewport& visualViewport = frame()->page()->frameHost().visualViewport();
     Element* inputBox = frame()->document()->getElementById("box");
 
     webViewImpl()->setPageScaleFactor(2);
 
     // The element is already in the view so the scrollIntoView shouldn't move
     // the viewport at all.
     webViewImpl()->setVisualViewportOffset(WebFloatPoint(250.25f, 100.25f));
     layoutViewportScrollableArea->setScrollPosition(DoublePoint(0, 900.75), ProgrammaticScroll);
     inputBox->scrollIntoViewIfNeeded(false);
 
-    EXPECT_POINT_EQ(DoublePoint(0, 900.75), layoutViewportScrollableArea->scrollPositionDouble());
+    EXPECT_POINT_EQ(DoublePoint(0, 900), layoutViewportScrollableArea->scrollPositionDouble());
     EXPECT_POINT_EQ(FloatPoint(250.25f, 100.25f), visualViewport.location());
 
     // Change the fractional part of the frameview to one that would round down.
     layoutViewportScrollableArea->setScrollPosition(DoublePoint(0, 900.125), ProgrammaticScroll);
     inputBox->scrollIntoViewIfNeeded(false);
 
-    EXPECT_POINT_EQ(DoublePoint(0, 900.125), layoutViewportScrollableArea->scrollPositionDouble());
+    EXPECT_POINT_EQ(DoublePoint(0, 900), layoutViewportScrollableArea->scrollPositionDouble());
     EXPECT_POINT_EQ(FloatPoint(250.25f, 100.25f), visualViewport.location());
 
     // Repeat both tests above with the visual viewport at a high fractional.
     webViewImpl()->setVisualViewportOffset(WebFloatPoint(250.875f, 100.875f));
     layoutViewportScrollableArea->setScrollPosition(DoublePoint(0, 900.75), ProgrammaticScroll);
     inputBox->scrollIntoViewIfNeeded(false);
 
-    EXPECT_POINT_EQ(DoublePoint(0, 900.75), layoutViewportScrollableArea->scrollPositionDouble());
+    EXPECT_POINT_EQ(DoublePoint(0, 900), layoutViewportScrollableArea->scrollPositionDouble());
     EXPECT_POINT_EQ(FloatPoint(250.875f, 100.875f), visualViewport.location());
 
     // Change the fractional part of the frameview to one that would round down.
     layoutViewportScrollableArea->setScrollPosition(DoublePoint(0, 900.125), ProgrammaticScroll);
     inputBox->scrollIntoViewIfNeeded(false);
 
-    EXPECT_POINT_EQ(DoublePoint(0, 900.125), layoutViewportScrollableArea->scrollPositionDouble());
+    EXPECT_POINT_EQ(DoublePoint(0, 900), layoutViewportScrollableArea->scrollPositionDouble());
     EXPECT_POINT_EQ(FloatPoint(250.875f, 100.875f), visualViewport.location());
 
     // Both viewports with a 0.5 fraction.
     webViewImpl()->setVisualViewportOffset(WebFloatPoint(250.5f, 100.5f));
     layoutViewportScrollableArea->setScrollPosition(DoublePoint(0, 900.5), ProgrammaticScroll);
     inputBox->scrollIntoViewIfNeeded(false);
 
-    EXPECT_POINT_EQ(DoublePoint(0, 900.5), layoutViewportScrollableArea->scrollPositionDouble());
+    EXPECT_POINT_EQ(DoublePoint(0, 900), layoutViewportScrollableArea->scrollPositionDouble());
     EXPECT_POINT_EQ(FloatPoint(250.5f, 100.5f), visualViewport.location());
 }
 
 // Top controls can make an unscrollable page temporarily scrollable, causing
 // a scroll clamp when the page is resized. Make sure this bug is fixed.
 // crbug.com/437620
 TEST_F(VisualViewportTest, TestResizeDoesntChangeScrollOffset)
 {
     RuntimeEnabledFeatures::setInertTopControlsEnabled(false);
     initializeWithAndroidSettings();
@@ skipping 673 matching lines @@
     webViewImpl()->handleInputEvent(pinchUpdate);
 
     VisualViewport& visualViewport = webViewImpl()->page()->frameHost().visualViewport();
     FrameView& frameView = *webViewImpl()->mainFrameImpl()->frameView();
 
     EXPECT_FLOAT_POINT_EQ(FloatPoint(50, 50), visualViewport.location());
     EXPECT_FLOAT_POINT_EQ(FloatPoint(0, 0), frameView.scrollPositionDouble());
 }
 
 } // namespace