[CRD iOS] Ignore touch event when the touch point is out of the canvas in direct input mode

remoting/client/ui/trackpad_input_strategy.cc

Index: remoting/client/ui/trackpad_input_strategy.cc
diff --git a/remoting/client/ui/trackpad_input_strategy.cc b/remoting/client/ui/trackpad_input_strategy.cc
index f2f5719eb9858db3149690378ea07dc848721d35..f136e57f63747e421764c88b1d2a79ecff0b1b11 100644
--- a/remoting/client/ui/trackpad_input_strategy.cc
+++ b/remoting/client/ui/trackpad_input_strategy.cc
@@ -54,10 +54,12 @@ bool TrackpadInputStrategy::HandlePan(const ViewMatrix::Vector2D& translation,
   return true;
 }
 
-void TrackpadInputStrategy::TrackTouchInput(
+bool TrackpadInputStrategy::TrackTouchInput(
     const ViewMatrix::Point& touch_point,
     const DesktopViewport& viewport) {
   // Do nothing. The cursor position is independent of the touch position.
+  // |touch_point| is always valid.
+  return true;
 }
 
 ViewMatrix::Point TrackpadInputStrategy::GetCursorPosition() const {