exo: Implement v6 of touch protocol including shape and frame event

components/exo/touch.cc

 // Copyright 2015 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 "components/exo/touch.h"
 
 #include "components/exo/surface.h"
 #include "components/exo/touch_delegate.h"
 #include "components/exo/wm_helper.h"
 #include "ui/aura/window.h"
@@ skipping 100 matching lines @@
         focus_->RemoveSurfaceObserver(this);
         focus_ = nullptr;
 
         // Cancel the full set of touch sequences as soon as one is canceled.
         touch_points_.clear();
         delegate_->OnTouchCancel();
       }
     } break;
     default:
       NOTREACHED();
-      break;
+      return;
   }
+  if (event->type() == ui::ET_TOUCH_PRESSED ||
+      event->type() == ui::ET_TOUCH_MOVED) {
+    delegate_->OnTouchShape(event->touch_id(),

[reveman, 2016/12/08 01:40:45]

Can you move this up into the switch cases above instead so we only send it if
the touch id is valid? That way we also avoid branching twice.

+                            event->pointer_details().radius_x,
+                            event->pointer_details().radius_y);
+  }
+  // todo(denniskempin): Extend ui::TouchEvent to signal end of sequence of

[reveman, 2016/12/08 01:40:45]

s/todo/TODO/

+  // touch events to send TouchFrame once after all touches have been updated.
+  delegate_->OnTouchFrame();

[reveman, 2016/12/08 01:40:45]

Move this up into the switch cases as well to avoid sending if touch_id is not
valid.

 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // SurfaceObserver overrides:
 
 void Touch::OnSurfaceDestroying(Surface* surface) {
   DCHECK(surface == focus_);
   focus_ = nullptr;
   surface->RemoveSurfaceObserver(this);
 
   // Cancel touch sequences.
   DCHECK_NE(touch_points_.size(), 0u);
   touch_points_.clear();
   delegate_->OnTouchCancel();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // Touch, private:
 
 Surface* Touch::GetEffectiveTargetForEvent(ui::Event* event) const {
   Surface* target =
       Surface::AsSurface(static_cast<aura::Window*>(event->target()));
   if (!target)
     return nullptr;
 
   return delegate_->CanAcceptTouchEventsForSurface(target) ? target : nullptr;
 }
 
 }  // namespace exo