Add tracing output for the name of an input event to Blink.

Source/web/WebViewImpl.cpp

 /*
  * Copyright (C) 2011, 2012 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 1790 matching lines @@
     return mainFrameImpl()->frameView()->horizontalScrollbar();
 }
 
 bool WebViewImpl::hasVerticalScrollbar()
 {
     return mainFrameImpl()->frameView()->verticalScrollbar();
 }
 
 const WebInputEvent* WebViewImpl::m_currentInputEvent = 0;
 
+// FIXME: autogenerate this kind of code, and use it throughout Blink rather than
+// the one-offs for subsets of these values.
+static const AtomicString* inputTypeToName(WebInputEvent::Type type)
+{
+    switch (type) {
+    case WebInputEvent::MouseDown:
+        return &EventTypeNames::mousedown;
+    case WebInputEvent::MouseUp:
+        return &EventTypeNames::mouseup;
+    case WebInputEvent::MouseMove:
+        return &EventTypeNames::mousemove;
+    case WebInputEvent::MouseEnter:
+        return &EventTypeNames::mouseenter;
+    case WebInputEvent::MouseLeave:
+        return &EventTypeNames::mouseleave;
+    case WebInputEvent::ContextMenu:
+        return &EventTypeNames::contextmenu;
+    case WebInputEvent::MouseWheel:
+        return &EventTypeNames::mousewheel;
+    case WebInputEvent::KeyDown:
+        return &EventTypeNames::keydown;
+    case WebInputEvent::KeyUp:
+        return &EventTypeNames::keyup;
+    case WebInputEvent::GestureScrollBegin:
+        return &EventTypeNames::gesturescrollstart;
+    case WebInputEvent::GestureScrollEnd:
+        return &EventTypeNames::gesturescrollend;
+    case WebInputEvent::GestureScrollUpdate:
+        return &EventTypeNames::gesturescrollupdate;
+    case WebInputEvent::TouchStart:
+        return &EventTypeNames::touchstart;
+    case WebInputEvent::TouchMove:
+        return &EventTypeNames::touchmove;
+    case WebInputEvent::TouchEnd:
+        return &EventTypeNames::touchend;
+    case WebInputEvent::TouchCancel:
+        return &EventTypeNames::touchcancel;
+    default:
+        return 0;
+    }
+}
+
 bool WebViewImpl::handleInputEvent(const WebInputEvent& inputEvent)
 {
     UserGestureNotifier notifier(m_autofillClient, &m_userGestureObserved);
     // On the first input event since page load, |notifier| instructs the
     // autofill client to unblock values of password input fields of any forms
     // on the page. There is a single input event, GestureTap, which can both
     // be the first event after page load, and cause a form submission. In that
     // case, the form submission happens before the autofill client is told
     // to unblock the password values, and so the password values are not
     // submitted. To avoid that, GestureTap is handled explicitly:
     if (inputEvent.type == WebInputEvent::GestureTap && m_autofillClient) {
         m_userGestureObserved = true;
         m_autofillClient->firstUserGestureObserved();
     }
 
-    TRACE_EVENT0("input", "WebViewImpl::handleInputEvent");
+    const AtomicString* inputEventName = inputTypeToName(inputEvent.type);
+    TRACE_EVENT1("input", "WebViewImpl::handleInputEvent", "type", inputEventName ? TRACE_STR_COPY(inputEventName->ascii().data()) : "unknown");
     // If we've started a drag and drop operation, ignore input events until
     // we're done.
     if (m_doingDragAndDrop)
         return true;
 
     if (m_devToolsAgent && m_devToolsAgent->handleInputEvent(m_page.get(), inputEvent))
         return true;
 
     // Report the event to be NOT processed by WebKit, so that the browser can handle it appropriately.
     if (m_ignoreInputEvents)
@@ skipping 2226 matching lines @@
     const PageScaleConstraints& constraints = m_pageScaleConstraintsSet.pageDefinedConstraints();
 
     if (!mainFrameImpl() || !mainFrameImpl()->frameView())
         return false;
 
     return mainFrameImpl()->frameView()->layoutSize().width() == m_size.width
         || (constraints.minimumScale == constraints.maximumScale && constraints.minimumScale != -1);
 }
 
 } // namespace blink