[DevTools] Disable touch emulation on devices with touch input.

Source/core/inspector/InspectorPageAgent.cpp

 /*
  * Copyright (C) 2011 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 1146 matching lines @@
     m_client->setShowFPSCounter(m_state->getBoolean(PageAgentState::pageAgentShowFPSCounter) && !m_deviceMetricsOverridden);
     m_client->setContinuousPaintingEnabled(m_state->getBoolean(PageAgentState::pageAgentContinuousPaintingEnabled) && !m_deviceMetricsOverridden);
 }
 
 void InspectorPageAgent::updateTouchEventEmulationInPage(bool enabled)
 {
     m_state->setBoolean(PageAgentState::touchEventEmulationEnabled, enabled);
     m_client->setTouchEventEmulationEnabled(enabled);
 }
 
-void InspectorPageAgent::setTouchEmulationEnabled(ErrorString*, bool enabled)
+void InspectorPageAgent::hasTouchInputs(ErrorString*, bool* result)
+{
+    *result = m_client->hasTouchInputs();
+}
+
+void InspectorPageAgent::setTouchEmulationEnabled(ErrorString* error, bool enabled)
 {
     if (m_state->getBoolean(PageAgentState::touchEventEmulationEnabled) == enabled)
         return;
+    if (enabled && m_client->hasTouchInputs()) {
+        if (error)
+            *error = "Device already supports touch input";
+        return;
+    }
     updateTouchEventEmulationInPage(enabled);
 }
 
 void InspectorPageAgent::setEmulatedMedia(ErrorString*, const String& media)
 {
     String currentMedia = m_state->getString(PageAgentState::pageAgentEmulatedMedia);
     if (media == currentMedia)
         return;
 
     m_state->setString(PageAgentState::pageAgentEmulatedMedia, media);
@@ skipping 45 matching lines @@
 }
 
 void InspectorPageAgent::setShowViewportSizeOnResize(ErrorString*, bool show, const bool* showGrid)
 {
     m_state->setBoolean(PageAgentState::showSizeOnResize, show);
     m_state->setBoolean(PageAgentState::showGridOnResize, showGrid && *showGrid);
 }
 
 } // namespace WebCore