Supports fake key events for setComposition/commitText by on-screen keyboards.

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index 8de58b9056aafe1da3215f3de603b8a99c412512..78838efa7d1d5e7d967847689b893d99ee8f1de9 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -1155,6 +1155,9 @@ void Shell::OnWindowActivated(aura::Window* gained_active,
                               aura::Window* lost_active) {
   if (gained_active)
     target_root_window_ = gained_active->GetRootWindow();
+  input_method_filter_->UpdateTargetDispatcher(
+      target_root_window_ ? target_root_window_->GetHost()->event_processor()
+                          : NULL);

[sadrul, 2014/05/31 18:10:16]

The problem with this is that all non-ash users of InputMethodEventFilters will
have to do the same thing (e.g. desktop, athena, etc).

A better solution would be for the IMEFilter to install itself as the
ActivationChangeObserver to the ActivationClient of the root-window, and update
the |target_dispatcher_| itself when appropriate.

[Shu Chen, 2014/06/01 05:33:23]

Done.

 }
 
 }  // namespace ash