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

Source/core/inspector/InspectorPageAgent.cpp

Index: Source/core/inspector/InspectorPageAgent.cpp
diff --git a/Source/core/inspector/InspectorPageAgent.cpp b/Source/core/inspector/InspectorPageAgent.cpp
index e01e26537b1821f181ab687d64dc7f8311da7fb1..4bae12ce06458947801c3106fa3e0593bf3ef1a9 100644
--- a/Source/core/inspector/InspectorPageAgent.cpp
+++ b/Source/core/inspector/InspectorPageAgent.cpp
@@ -1164,10 +1164,20 @@ void InspectorPageAgent::updateTouchEventEmulationInPage(bool 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);
 }