Refactoring the ownership of ui::InputMethod.

ash/display/display_controller.cc

Index: ash/display/display_controller.cc
diff --git a/ash/display/display_controller.cc b/ash/display/display_controller.cc
index f34ae1fefc01e1040d4fa06bdef4002bc4a89de0..3d0d34820f941dc838c13ad1feafcc8ca9a3e4dc 100644
--- a/ash/display/display_controller.cc
+++ b/ash/display/display_controller.cc
@@ -38,6 +38,7 @@
 #include "ui/aura/window_property.h"
 #include "ui/aura/window_tracker.h"
 #include "ui/aura/window_tree_host.h"
+#include "ui/base/ime/input_method_factory.h"
 #include "ui/compositor/compositor.h"
 #include "ui/gfx/display.h"
 #include "ui/gfx/screen.h"
@@ -879,6 +880,11 @@ AshWindowTreeHost* DisplayController::AddWindowTreeHostForDisplay(
       display.id() == DisplayManager::kUnifiedDisplayId;
   AshWindowTreeHost* ash_host = AshWindowTreeHost::Create(params_with_bounds);
   aura::WindowTreeHost* host = ash_host->AsWindowTreeHost();
+  if (!input_method_) {  // Singleton input method instance for Ash.
+    input_method_ = ui::CreateInputMethod(host, host->GetAcceleratedWidget());
+    input_method_->OnFocus();
+  }
+  host->SetInputMethod(input_method_.get());
 
   host->window()->SetName(base::StringPrintf(
       "%sRootWindow-%d", params_with_bounds.offscreen ? "Offscreen" : "",