Fix icon on Windows XP taskbar

ui/gfx/win/window_impl.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 "ui/gfx/win/window_impl.h"
 
 #include <list>
 
 #include "base/bind.h"
 #include "base/debug/alias.h"
@@ skipping 15 matching lines @@
 
 // Several external scripts rely explicitly on this base class name for
 // acquiring the window handle and will break if this is modified!
 // static
 const wchar_t* const WindowImpl::kBaseClassName = L"Chrome_WidgetWin_";
 
 // WindowImpl class information used for registering unique windows.
 struct ClassInfo {
   UINT style;
   HICON icon;
+  HICON small_icon;
 
-  ClassInfo(int style, HICON icon)
+  ClassInfo(int style, HICON icon, HICON small_icon)
       : style(style),
-        icon(icon) {}
+        icon(icon),
+        small_icon(small_icon) {}
 
   // Compares two ClassInfos. Returns true if all members match.
   bool Equals(const ClassInfo& other) const {
     return (other.style == style && other.icon == icon);
   }
 };
 
 // WARNING: this class may be used on multiple threads.
 class ClassRegistrar {
  public:
@@ skipping 78 matching lines @@
   base::win::InitializeWindowClass(
       name.c_str(),
       &base::win::WrappedWindowProc<WindowImpl::WndProc>,
       class_info.style,
       0,
       0,
       NULL,
       reinterpret_cast<HBRUSH>(GetStockObject(BLACK_BRUSH)),
       NULL,
       class_info.icon,
-      class_info.icon,
+      class_info.small_icon,
       &window_class);
   HMODULE instance = window_class.hInstance;
   ATOM atom = RegisterClassEx(&window_class);
   CHECK(atom) << GetLastError();
 
   registered_classes_.push_back(RegisteredClass(
       class_info, name, atom, instance));
 
   return atom;
 }
@@ skipping 103 matching lines @@
   CheckWindowCreated(hwnd_);
 
   // The window procedure should have set the data for us.
   CHECK_EQ(this, GetWindowUserData(hwnd));
 }
 
 HICON WindowImpl::GetDefaultWindowIcon() const {
   return NULL;
 }
 
+HICON WindowImpl::GetSmallWindowIcon() const {
+  return NULL;

[sky, 2014/12/01 17:35:52]

If possible, nullptr every where.

+}
+
 LRESULT WindowImpl::OnWndProc(UINT message, WPARAM w_param, LPARAM l_param) {
   LRESULT result = 0;
 
   HWND hwnd = hwnd_;
   if (message == WM_NCDESTROY)
     hwnd_ = NULL;
 
   // Handle the message if it's in our message map; otherwise, let the system
   // handle it.
   if (!ProcessWindowMessage(hwnd, message, w_param, l_param, result))
@@ skipping 26 matching lines @@
 
   WindowImpl* window = reinterpret_cast<WindowImpl*>(GetWindowUserData(hwnd));
   if (!window)
     return 0;
 
   return window->OnWndProc(message, w_param, l_param);
 }
 
 ATOM WindowImpl::GetWindowClassAtom() {
   HICON icon = GetDefaultWindowIcon();
-  ClassInfo class_info(initial_class_style(), icon);
+  HICON small_icon = GetSmallWindowIcon();
+  ClassInfo class_info(initial_class_style(), icon, small_icon);
   return ClassRegistrar::GetInstance()->RetrieveClassAtom(class_info);
 }
 
 }  // namespace gfx