text input focus: Supports Window::GetFocusedTextInputClient.

ui/aura/demo/demo_main.cc

 // Copyright (c) 2012 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 "base/at_exit.h"
 #include "base/command_line.h"
 #include "base/i18n/icu_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "third_party/skia/include/core/SkXfermode.h"
@@ skipping 27 matching lines @@
  public:
   explicit DemoWindowDelegate(SkColor color) : color_(color) {}
 
   // Overridden from 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 {}
+  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 HTCAPTION;
   }
   bool ShouldDescendIntoChildForEventHandling(
       aura::Window* child,
       const gfx::Point& location) override {
     return true;
@@ skipping 16 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(DemoWindowDelegate);
 };
 
 class DemoWindowTreeClient : public aura::client::WindowTreeClient {
  public:
   explicit DemoWindowTreeClient(aura::Window* window) : window_(window) {
     aura::client::SetWindowTreeClient(window_, this);
   }
 
   ~DemoWindowTreeClient() override {
-    aura::client::SetWindowTreeClient(window_, NULL);
+    aura::client::SetWindowTreeClient(window_, nullptr);
   }
 
   // Overridden from aura::client::WindowTreeClient:
   aura::Window* GetDefaultParent(aura::Window* context,
                                  aura::Window* window,
                                  const gfx::Rect& bounds) override {
     if (!capture_client_) {
       capture_client_.reset(
           new aura::client::DefaultCaptureClient(window_->GetRootWindow()));
     }
@@ skipping 77 matching lines @@
 int main(int argc, char** argv) {
   base::CommandLine::Init(argc, argv);
 
   // The exit manager is in charge of calling the dtors of singleton objects.
   base::AtExitManager exit_manager;
 
   base::i18n::InitializeICU();
 
   return DemoMain();
 }