Remove the 2-level input method system & InputMethodBridge.

ash/display/cursor_window_controller.cc

Index: ash/display/cursor_window_controller.cc
diff --git a/ash/display/cursor_window_controller.cc b/ash/display/cursor_window_controller.cc
index 17149ac88a2c47d66c9b0410270be05c5a1e0cb9..3594937a55e53142831138296ead183d737a907c 100644
--- a/ash/display/cursor_window_controller.cc
+++ b/ash/display/cursor_window_controller.cc
@@ -34,7 +34,6 @@ class CursorWindowDelegate : public aura::WindowDelegate {
   gfx::Size GetMaximumSize() const override { return size_; }
   void OnBoundsChanged(const gfx::Rect& old_bounds,
                        const gfx::Rect& new_bounds) override {}
-  ui::TextInputClient* GetFocusedTextInputClient() override { return nullptr; }
   gfx::NativeCursor GetCursor(const gfx::Point& point) override {
     return gfx::kNullCursor;
   }