Change hover element to scrollbar's parent when hit test contains scrollbar

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

Index: third_party/WebKit/Source/web/tests/WebFrameTest.cpp
diff --git a/third_party/WebKit/Source/web/tests/WebFrameTest.cpp b/third_party/WebKit/Source/web/tests/WebFrameTest.cpp
index d123a03ceffb17247de312433aaba890b5e7b4b9..1525a93661764deac91d9914bb81e38c4089f344 100644
--- a/third_party/WebKit/Source/web/tests/WebFrameTest.cpp
+++ b/third_party/WebKit/Source/web/tests/WebFrameTest.cpp
@@ -10833,7 +10833,7 @@ TEST_F(WebFrameTest, MouseOverDifferntNodeClearsTooltip) {
 }
 
 // Makes sure that mouse hover over an overlay scrollbar doesn't activate
-// elements below unless the scrollbar is faded out.
+// elements below(not the scrollbar's parent) unless the scrollbar is faded out.

[bokan, 2017/02/02 23:29:26]

I'd change this to "except the Element that owns the scrollbar"

 TEST_F(WebFrameTest, MouseOverLinkAndOverlayScrollbar) {
   FrameTestHelpers::WebViewHelper webViewHelper;
   webViewHelper.initialize(true, nullptr, nullptr, nullptr,
@@ -10995,6 +10995,61 @@ TEST_F(WebFrameTest, MouseOverCustomScrollbar) {
   EXPECT_EQ(hitTestResult.scrollbar()->hoveredPart(), ScrollbarPart::ThumbPart);
 }
 
+// Makes sure that mouse hover over a scrollbar also hover the element owns the
+// scrollbar.
+TEST_F(WebFrameTest, MouseOverScrollbarAndParentElement) {
+  registerMockedHttpURLLoad("scrollbar-and-element-hover.html");
+  FrameTestHelpers::WebViewHelper webViewHelper;
+  WebViewImpl* webView = webViewHelper.initializeAndLoad(
+      m_baseURL + "scrollbar-and-element-hover.html");
+
+  webViewHelper.resize(WebSize(200, 200));
+
+  webView->updateAllLifecyclePhases();
+
+  Document* document = toLocalFrame(webView->page()->mainFrame())->document();
+
+  Element* scrollbarDiv = document->getElementById("scrollbar");
+  EXPECT_TRUE(scrollbarDiv);
+
+  // Ensure hittest only has DIV.
+  HitTestResult hitTestResult = webView->coreHitTestResultAt(WebPoint(1, 1));
+
+  EXPECT_TRUE(hitTestResult.innerElement());
+  EXPECT_FALSE(hitTestResult.scrollbar());
+
+  // Mouse over DIV.
+  WebMouseEvent mouseMoveOverDiv(
+      WebInputEvent::MouseMove, WebFloatPoint(1, 1), WebFloatPoint(1, 1),
+      WebPointerProperties::Button::NoButton, 0, WebInputEvent::NoModifiers,
+      TimeTicks::Now().InSeconds());
+  mouseMoveOverDiv.setFrameScale(1);
+  document->frame()->eventHandler().handleMouseMoveEvent(
+      mouseMoveOverDiv, Vector<WebMouseEvent>());
+
+  // DIV :hover.
+  EXPECT_EQ(document->hoverNode(), scrollbarDiv);
+
+  // Ensure hittest has DIV and scrollbar.
+  hitTestResult = webView->coreHitTestResultAt(WebPoint(175, 5));
+
+  EXPECT_TRUE(hitTestResult.innerElement());
+  EXPECT_TRUE(hitTestResult.scrollbar());
+  EXPECT_FALSE(hitTestResult.scrollbar()->isCustomScrollbar());
+
+  // Mouse over scrollbar.
+  WebMouseEvent mouseMoveOverDivAndScrollbar(
+      WebInputEvent::MouseMove, WebFloatPoint(175, 5), WebFloatPoint(175, 5),
+      WebPointerProperties::Button::NoButton, 0, WebInputEvent::NoModifiers,
+      TimeTicks::Now().InSeconds());
+  mouseMoveOverDivAndScrollbar.setFrameScale(1);
+  document->frame()->eventHandler().handleMouseMoveEvent(
+      mouseMoveOverDivAndScrollbar, Vector<WebMouseEvent>());
+
+  // Not change the DIV :hover.
+  EXPECT_EQ(document->hoverNode(), scrollbarDiv);
+}

[bokan, 2017/02/02 23:29:26]

I think it'll work, but please add to this test case a check for when a
scrollbar exists but is disabled due to no overflow. i.e. remove the inner div
and (as commented below) make the scroller div overflow: scroll so that removing
the inner div will keep the scrollbar but disable it. Hovering over the disabled
scrollbar should still apply hover to the div.

+
 TEST_F(WebFrameTest, MouseReleaseUpdatesScrollbarHoveredPart) {
   registerMockedHttpURLLoad("custom-scrollbar-hover.html");
   FrameTestHelpers::WebViewHelper webViewHelper;