Auto merge of #21688 - paulrouget:rm-clipboard, r=jdm

Let the clipboard crate handle the lack of clipboard support

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ports/libsimpleservo/src/api.rs

@@ -437,11 +437,6 @@ impl WindowMethods for ServoCallbacks {
         self.host_callbacks.flush();
     }
 
-    fn supports_clipboard(&self) -> bool {
-        debug!("WindowMethods::supports_clipboard");
-        false
-    }
-
     fn create_event_loop_waker(&self) -> Box<EventLoopWaker> {
         debug!("WindowMethods::create_event_loop_waker");
         self.waker.clone()

ports/servo/glutin_app/window.rs

@@ -813,10 +813,6 @@ impl WindowMethods for Window {
     ) -> bool {
         true
     }
-
-    fn supports_clipboard(&self) -> bool {
-        true
-    }
 }
 
 fn winit_phase_to_touch_event_type(phase: TouchPhase) -> TouchEventType {