mus: Add watcher for all touch events.

services/ui/ws/window_tree.cc

 // Copyright 2014 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 "services/ui/ws/window_tree.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 1139 matching lines @@
                                   uint32_t observer_id) {
   if (matcher.is_null() || observer_id == 0) {
     // Clear any existing event observer.
     event_observer_matcher_.reset();
     event_observer_id_ = 0;
     return;
   }
 
   // Do not allow key events to be observed, as a compromised app could register
   // itself as an event observer and spy on keystrokes to another app.
-  if (!matcher->type_matcher) {
+  if (!matcher->type_matcher && !matcher->pointer_kind_matcher) {
     DVLOG(1) << "SetEventObserver must specify an event type.";
     return;
   }
+
   const ui::mojom::EventType event_type_whitelist[] = {
       ui::mojom::EventType::POINTER_CANCEL, ui::mojom::EventType::POINTER_DOWN,
       ui::mojom::EventType::POINTER_MOVE,   ui::mojom::EventType::POINTER_UP,
       ui::mojom::EventType::MOUSE_EXIT,     ui::mojom::EventType::WHEEL,
   };
+  const ui::mojom::PointerKind pointer_kind_whitelist[] = {
+      ui::mojom::PointerKind::MOUSE, ui::mojom::PointerKind::TOUCH,
+  };
+
   bool allowed = false;
-  for (ui::mojom::EventType event_type : event_type_whitelist) {
-    if (matcher->type_matcher->type == event_type) {
-      allowed = true;
-      break;
+  if (matcher->type_matcher) {
+    for (ui::mojom::EventType event_type : event_type_whitelist) {
+      if (matcher->type_matcher->type == event_type) {
+        allowed = true;
+        break;
+      }
+    }
+  } else if (matcher->pointer_kind_matcher) {

[sky, 2016/07/06 20:22:02]

Shouldn't this conditional be a standalone if? That is, if a type_matcher is
specified you validate it, and if a pointer_kind_matcher is specified you
validate it too?

[riajiang, 2016/07/08 02:51:40]

Yes, changed it to a standalone if.

+    for (ui::mojom::PointerKind pointer : pointer_kind_whitelist) {
+      if (matcher->pointer_kind_matcher->pointer_kind == pointer) {
+        allowed = true;
+        break;
+      }
     }
   }
   if (!allowed) {
     DVLOG(1) << "SetEventObserver event type not allowed";
     return;
   }
 
   event_observer_matcher_.reset(new EventMatcher(*matcher));
   event_observer_id_ = observer_id;
 }
@@ skipping 346 matching lines @@
 }
 
 bool WindowTree::IsWindowRootOfAnotherTreeForAccessPolicy(
     const ServerWindow* window) const {
   WindowTree* tree = window_server_->GetTreeWithRoot(window);
   return tree && tree != this;
 }
 
 }  // namespace ws
 }  // namespace ui