Remove some probably dead code in EventHandler::handleDrag.

Source/core/page/EventHandler.cpp

Index: Source/core/page/EventHandler.cpp
diff --git a/Source/core/page/EventHandler.cpp b/Source/core/page/EventHandler.cpp
index 0d2af190fdadcaf713ea859b70be696606655e3a..a41eb7f250b6b72015824c735104d1144312bb51 100644
--- a/Source/core/page/EventHandler.cpp
+++ b/Source/core/page/EventHandler.cpp
@@ -650,14 +650,14 @@ bool EventHandler::handleMouseDraggedEvent(const MouseEventWithHitTestResults& e
 {
     TRACE_EVENT0("blink", "EventHandler::handleMouseDraggedEvent");
 
-    if (!m_mousePressed)
+    if (!m_mousePressed || event.event().button() != LeftButton)

[Rick Byers, 2014/11/14 18:29:28]

You said this case is "probably dead".  Should we perhaps add an ASSERT to see
if we can catch anyone trying to do a drag without the left button being
pressed?  If there are any such cases, it could be a compat bug...

[dcheng, 2014/11/14 18:41:26]

The thing is, we always bailed out anyway if it wasn't a left button drag. The
check was just done in two different places before--once at the beginning
handleDrag(), and once after handleDrag() returned. The check has been
consolidated into one place.

The other possibility is someone passing in a MouseEvent that's not a MouseMoved
event. In that case, we would skip the HTML drag steps, but not skip the default
drag handling steps. It seems a bit silly to do that, so now, we go through the
same set of steps for both.

         return false;
 
     if (handleDrag(event, DragInitiator::Mouse))
         return true;
 
     Node* targetNode = event.innerNode();
-    if (event.event().button() != LeftButton || !targetNode)
+    if (!targetNode)
         return false;
 
     RenderObject* renderer = targetNode->renderer();
@@ -3209,16 +3209,6 @@ bool EventHandler::handleDrag(const MouseEventWithHitTestResults& event, DragIni
     if (!m_frame->page())
         return false;
 
-    // FIXME: Does this ever get hit??
-    if (event.event().button() != LeftButton || event.event().type() != PlatformEvent::MouseMoved) {
-        // If we allowed the other side of the bridge to handle a drag
-        // last time, then m_mousePressed might still be set. So we
-        // clear it now to make sure the next move after a drag
-        // doesn't look like a drag.
-        m_mousePressed = false;
-        return false;
-    }
-
     if (m_mouseDownMayStartDrag) {
         HitTestRequest request(HitTestRequest::ReadOnly);
         HitTestResult result(m_mouseDownPos);