text input focus: Supports Window::GetFocusedTextInputClient.

ui/keyboard/keyboard_controller.cc

 // Copyright (c) 2013 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 "ui/keyboard/keyboard_controller.h"
 
 #include <set>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 75 matching lines @@
   ~KeyboardWindowDelegate() override {}
 
  private:
   // Overridden from aura::WindowDelegate:
   gfx::Size GetMinimumSize() const override { return gfx::Size(); }
   gfx::Size GetMaximumSize() const override { return gfx::Size(); }
   void OnBoundsChanged(const gfx::Rect& old_bounds,
                        const gfx::Rect& new_bounds) override {
     bounds_ = new_bounds;
   }
+  ui::TextInputClient* GetFocusedTextInputClient() override {
+    return nullptr;
+  }
   gfx::NativeCursor GetCursor(const gfx::Point& point) override {
     return gfx::kNullCursor;
   }
   int GetNonClientComponent(const gfx::Point& point) const override {
     return HTNOWHERE;
   }
   bool ShouldDescendIntoChildForEventHandling(
       aura::Window* child,
       const gfx::Point& location) override {
     return true;
@@ skipping 458 matching lines @@
   proxy_->HideKeyboardContainer(container_.get());
 }
 
 void KeyboardController::AddBoundsChangedObserver(aura::Window* window) {
   aura::Window* target_window = window ? window->GetToplevelWindow() : nullptr;
   if (target_window)
     window_bounds_observer_->AddObservedWindow(target_window);
 }
 
 }  // namespace keyboard