Move touch CTM from X into Chrome

ui/aura/window_tree_host.h

Index: ui/aura/window_tree_host.h
diff --git a/ui/aura/window_tree_host.h b/ui/aura/window_tree_host.h
index 9d54944777f1dfb776868485abfc1dad1d8749cf..980a1b52adcc02fb33341174221967473d286085 100644
--- a/ui/aura/window_tree_host.h
+++ b/ui/aura/window_tree_host.h
@@ -116,6 +116,15 @@ class AURA_EXPORT WindowTreeHost {
 
   gfx::NativeCursor last_cursor() const { return last_cursor_; }
 
+  void UpdateDisplayID(int64 id1, int64 id2) {
+    display_ids_.first = id1;
+    display_ids_.second = id2;
+  }
+
+  const std::pair<int64, int64>& display_ids() const {
+     return display_ids_;
+  }
+
   // Returns the EventSource responsible for dispatching events to the window
   // tree.
   virtual ui::EventSource* GetEventSource() = 0;
@@ -198,6 +207,13 @@ class AURA_EXPORT WindowTreeHost {
 
   scoped_ptr<ui::ViewProp> prop_;
 
+  // The display IDs associated with this root window.
+  // In single monitor or extended mode dual monitor case, the root window
+  // is associated with one display.
+  // In mirror mode dual monitors case, the root window is associated with
+  // both displays.
+  std::pair<int64, int64> display_ids_;

[oshima, 2014/05/01 09:35:42]

this can move to ash_window_tree_host_x11 now?

[Yufeng Shen (Slow to review), 2014/05/01 22:43:48]

In touch_transformer_controller.cc I need to get a hold
of WindowTreeHost* to call UpdateDisplayID().
The way I do is calling
display_controller->GetPrimaryRootWindow()/GetRootWindowForDisplayID(id)->GetHost()

How can I get a hold of AshWindowTreeHost* ? 
Do you think we should expose similar getter to query
DisplayController::window_tree_hosts_ to return AshWindowTreeHost* ?

[oshima, 2014/05/01 23:07:56]

You can use RootWindowController()->ash_host()

[Yufeng Shen (Slow to review), 2014/05/02 00:03:39]

Done.

+
   DISALLOW_COPY_AND_ASSIGN(WindowTreeHost);
 };