[DevTools] Allow touch emulation on devices with native touch.

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 1319 matching lines @@
 }
 
 void InspectorPageAgent::updateTouchEventEmulationInPage(bool enabled)
 {
     if (!m_touchEmulationEnabled) {
         m_originalTouchEnabled = RuntimeEnabledFeatures::touchEnabled();
         m_originalDeviceSupportsMouse = m_page->settings().deviceSupportsMouse();
         m_originalDeviceSupportsTouch = m_page->settings().deviceSupportsTouch();
     }
     RuntimeEnabledFeatures::setTouchEnabled(enabled ? true : m_originalTouchEnabled);
-    m_page->settings().setDeviceSupportsMouse(enabled ? false : m_originalDeviceSupportsMouse);
-    m_page->settings().setDeviceSupportsTouch(enabled ? true : m_originalDeviceSupportsTouch);
+    if (!m_originalDeviceSupportsTouch) {
+        m_page->settings().setDeviceSupportsMouse(enabled ? false : m_originalDeviceSupportsMouse);
+        m_page->settings().setDeviceSupportsTouch(enabled ? true : m_originalDeviceSupportsTouch);
+    }
     m_touchEmulationEnabled = enabled;
     m_client->setTouchEventEmulationEnabled(enabled);
     m_page->deprecatedLocalMainFrame()->view()->layout();
 }
 
-void InspectorPageAgent::hasTouchInputs(ErrorString*, bool* result)
-{
-    *result = m_touchEmulationEnabled ? m_originalDeviceSupportsTouch : m_page->settings().deviceSupportsTouch();
-}
-
-void InspectorPageAgent::setTouchEmulationEnabled(ErrorString* error, bool enabled)
+void InspectorPageAgent::setTouchEmulationEnabled(ErrorString*, bool enabled)
 {
     if (m_state->getBoolean(PageAgentState::touchEventEmulationEnabled) == enabled)
         return;
 
-    bool hasTouch = false;
-    hasTouchInputs(error, &hasTouch);
-    if (enabled && hasTouch) {
-        if (error)
-            *error = "Device already supports touch input";
-        return;
-    }
-
     m_state->setBoolean(PageAgentState::touchEventEmulationEnabled, enabled);
     updateTouchEventEmulationInPage(enabled);
 }
 
 void InspectorPageAgent::setEmulatedMedia(ErrorString*, const String& media)
 {
     String currentMedia = m_state->getString(PageAgentState::pageAgentEmulatedMedia);
     if (media == currentMedia)
         return;
 
@@ skipping 63 matching lines @@
 }
 
 void InspectorPageAgent::trace(Visitor* visitor)
 {
     visitor->trace(m_page);
     InspectorBaseAgent::trace(visitor);
 }
 
 } // namespace blink