Start sending auxclick instead of click for non-primary buttons

third_party/WebKit/Source/core/input/EventHandler.cpp

Index: third_party/WebKit/Source/core/input/EventHandler.cpp
diff --git a/third_party/WebKit/Source/core/input/EventHandler.cpp b/third_party/WebKit/Source/core/input/EventHandler.cpp
index 0d12edaba07fdd4422f52c88d0470b388c743200..69ea301be75d9697b8bbe72cc4ef1c08d61ded12 100644
--- a/third_party/WebKit/Source/core/input/EventHandler.cpp
+++ b/third_party/WebKit/Source/core/input/EventHandler.cpp
@@ -1150,16 +1150,18 @@ WebInputEventResult EventHandler::handleMouseReleaseEvent(const PlatformMouseEve
 
     WebInputEventResult eventResult = updatePointerTargetAndDispatchEvents(EventTypeNames::mouseup, mev.innerNode(), m_clickCount, mev.event());
 
-    bool contextMenuEvent = mouseEvent.button() == RightButton;
+    // We only prevent click event when the click may cause contextmenu to popup.
+    // However, we always send auxclick.
+    bool macContextMenuEvent = false;
 #if OS(MACOSX)
     // FIXME: The Mac port achieves the same behavior by checking whether the context menu is currently open in WebPage::mouseEvent(). Consider merging the implementations.
     if (mouseEvent.button() == LeftButton && mouseEvent.getModifiers() & PlatformEvent::CtrlKey)
-        contextMenuEvent = true;
+        macContextMenuEvent = true;
 #endif
 
     WebInputEventResult clickEventResult = WebInputEventResult::NotHandled;
     const bool shouldDispatchClickEvent = m_clickCount > 0
-        && !contextMenuEvent
+        && !macContextMenuEvent
         && mev.innerNode() && m_clickNode
         && mev.innerNode()->canParticipateInFlatTree() && m_clickNode->canParticipateInFlatTree()
         && !(selectionController().hasExtendedSelection() && isLinkSelection(mev));
@@ -1183,7 +1185,10 @@ WebInputEventResult EventHandler::handleMouseReleaseEvent(const PlatformMouseEve
             // correctly. Moreover, clickTargetNode is different from
             // mev.innerNode at drag-release.
             clickEventResult = toWebInputEventResult(clickTargetNode->dispatchMouseEvent(mev.event(),
-                EventTypeNames::click, m_clickCount));
+                !RuntimeEnabledFeatures::auxclickEnabled() || (mev.event().button() == MouseButton::LeftButton)
+                    ? EventTypeNames::click
+                    : EventTypeNames::auxclick,

[Dan Beam, 2016/08/09 02:04:34]

so this guarantees there'll always be either 'click' with button == 1 OR an
'auxclick'?

[Navid Zolghadr, 2016/08/09 13:34:46]

That is correct. After this change for the primary button (which is Left mouse
button for example with enum value 0) we send click event and for all other
buttons we send auxclick. These events will have the exact same properties and
everything. So the previous js codes should just work listening to auxclick
instead of click or listening to both if they want.

+                m_clickCount));
         }
     }