[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

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "remoting/client/ui/trackpad_input_strategy.h"
 
 #include "remoting/client/ui/desktop_viewport.h"
 
 namespace remoting {
 
@@ skipping 36 matching lines @@
   cursor_position_.x += translation_on_desktop.x;
   cursor_position_.y += translation_on_desktop.y;
 
   cursor_position_ = viewport->ConstrainPointToDesktop(cursor_position_);
 
   // Keep the cursor on focus.
   viewport->SetViewportCenter(cursor_position_.x, cursor_position_.y);
   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 {
   return cursor_position_;
 }
 
 ViewMatrix::Vector2D TrackpadInputStrategy::MapScreenVectorToDesktop(
     const ViewMatrix::Vector2D& delta,
     const DesktopViewport& viewport) const {
   // No conversion is needed for trackpad mode.
   return delta;
 }
 
 float TrackpadInputStrategy::GetFeedbackRadius(InputFeedbackType type) const {
   switch (type) {
     case InputFeedbackType::TAP_FEEDBACK:
       return kTapFeedbackRadius;
     case InputFeedbackType::DRAG_FEEDBACK:
       return kDragFeedbackRadius;
   }
   NOTREACHED();
   return 0.f;
 }
 
 bool TrackpadInputStrategy::IsCursorVisible() const {
   return true;
 }
 }  // namespace remoting