Remove Aero Peek Tabs code.

BUG=8036
TEST=Checked --enable-aero-peek-tabs does not take effect

Review URL: http://codereview.chromium.org/10368027

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@135583 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 0 insertions, 1031 deletions

diff --git a/chrome/browser/aeropeek_manager.cc b/chrome/browser/aeropeek_manager.cc
deleted file mode 100644
index e00242a..0000000
--- a/chrome/browser/aeropeek_manager.cc
+++ /dev/null
@@ -1,1031 +0,0 @@
-// 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 "chrome/browser/aeropeek_manager.h"
-
-#include <dwmapi.h>
-#include <shobjidl.h>
-
-#include "base/bind.h"
-#include "base/command_line.h"
-#include "base/scoped_native_library.h"
-#include "base/synchronization/waitable_event.h"
-#include "base/win/scoped_comptr.h"
-#include "base/win/scoped_gdi_object.h"
-#include "base/win/scoped_hdc.h"
-#include "base/win/windows_version.h"
-#include "chrome/browser/app_icon_win.h"
-#include "chrome/browser/browser_process.h"
-#include "chrome/browser/favicon/favicon_tab_helper.h"
-#include "chrome/browser/sessions/restore_tab_helper.h"
-#include "chrome/browser/tab_contents/thumbnail_generator.h"
-#include "chrome/browser/tabs/tab_strip_model.h"
-#include "chrome/browser/ui/browser_list.h"
-#include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
-#include "chrome/common/chrome_constants.h"
-#include "chrome/common/chrome_switches.h"
-#include "chrome/installer/util/browser_distribution.h"
-#include "content/public/browser/browser_thread.h"
-#include "content/public/browser/render_view_host.h"
-#include "content/public/browser/render_widget_host_view.h"
-#include "content/public/browser/web_contents.h"
-#include "content/public/browser/web_contents_delegate.h"
-#include "content/public/browser/web_contents_view.h"
-#include "skia/ext/image_operations.h"
-#include "skia/ext/platform_canvas.h"
-#include "third_party/skia/include/core/SkBitmap.h"
-#include "ui/base/win/shell.h"
-#include "ui/base/win/window_impl.h"
-#include "ui/gfx/gdi_util.h"
-#include "ui/gfx/icon_util.h"
-#include "ui/views/widget/native_widget_win.h"
-
-#pragma comment(lib, "dwmapi.lib")
-
-using content::BrowserThread;
-using content::WebContents;
-
-namespace {
-
-// Sends a thumbnail bitmap to Windows. Windows assumes this function is called
-// when a WM_DWMSENDICONICTHUMBNAIL message sent to a place-holder window. We
-// can use DwmInvalidateIconicBitmap() to force Windows to send the message.
-HRESULT CallDwmSetIconicThumbnail(HWND window, HBITMAP bitmap, DWORD flags) {
-  FilePath dwmapi_path(base::GetNativeLibraryName(L"dwmapi"));
-  base::ScopedNativeLibrary dwmapi(dwmapi_path);
-
-  typedef HRESULT (STDAPICALLTYPE *DwmSetIconicThumbnailProc)(
-      HWND, HBITMAP, DWORD);
-  DwmSetIconicThumbnailProc dwm_set_iconic_thumbnail =
-      static_cast<DwmSetIconicThumbnailProc>(
-      dwmapi.GetFunctionPointer("DwmSetIconicThumbnail"));
-
-  if (!dwm_set_iconic_thumbnail)
-    return E_FAIL;
-
-  return dwm_set_iconic_thumbnail(window, bitmap, flags);
-}
-
-// Sends a preview bitmap to Windows. Windows assumes this function is called
-// when a WM_DWMSENDICONICLIVEPREVIEWBITMAP message sent to a place-holder
-// window.
-HRESULT CallDwmSetIconicLivePreviewBitmap(HWND window,
-                                          HBITMAP bitmap,
-                                          POINT* client,
-                                          DWORD flags) {
-  FilePath dwmapi_path(base::GetNativeLibraryName(L"dwmapi"));
-  base::ScopedNativeLibrary dwmapi(dwmapi_path);
-
-  typedef HRESULT (STDAPICALLTYPE *DwmSetIconicLivePreviewBitmapProc)(
-      HWND, HBITMAP, POINT*, DWORD);
-  DwmSetIconicLivePreviewBitmapProc dwm_set_live_preview_bitmap =
-      static_cast<DwmSetIconicLivePreviewBitmapProc>(
-      dwmapi.GetFunctionPointer("DwmSetIconicLivePreviewBitmap"));
-
-  if (!dwm_set_live_preview_bitmap)
-    return E_FAIL;
-
-  return dwm_set_live_preview_bitmap(window, bitmap, client, flags);
-}
-
-// Invalidates the thumbnail image of the specified place-holder window. (See
-// the comments in CallDwmSetIconicThumbnai()).
-HRESULT CallDwmInvalidateIconicBitmaps(HWND window) {
-  FilePath dwmapi_path(base::GetNativeLibraryName(L"dwmapi"));
-  base::ScopedNativeLibrary dwmapi(dwmapi_path);
-
-  typedef HRESULT (STDAPICALLTYPE *DwmInvalidateIconicBitmapsProc)(HWND);
-  DwmInvalidateIconicBitmapsProc dwm_invalidate_iconic_bitmaps =
-      static_cast<DwmInvalidateIconicBitmapsProc>(
-      dwmapi.GetFunctionPointer("DwmInvalidateIconicBitmaps"));
-
-  if (!dwm_invalidate_iconic_bitmaps)
-    return E_FAIL;
-
-  return dwm_invalidate_iconic_bitmaps(window);
-}
-
-void CopyFromBackingStoreComplete(bool* result, bool* done, bool succeeded) {
-  *result = succeeded;
-  *done = true;
-}
-
-}  // namespace
-
-namespace {
-
-// These callbacks indirectly access the specified tab through the
-// AeroPeekWindowDelegate interface to prevent these tasks from accessing the
-// deleted tabs.
-
-// A callback that registers a thumbnail window as a child of the specified
-// browser application.
-void RegisterThumbnailCallback(HWND frame_window, HWND window, bool active) {
-  // Set the App ID of the browser for this place-holder window to tell
-  // that this window is a child of the browser application, i.e. to tell
-  // that this thumbnail window should be displayed when we hover the
-  // browser icon in the taskbar.
-  // TODO(mattm): This should use ShellIntegration::GetChromiumAppId to work
-  // properly with multiple profiles.
-  ui::win::SetAppIdForWindow(
-      BrowserDistribution::GetDistribution()->GetBrowserAppId(), window);
-
-  // Register this place-holder window to the taskbar as a child of
-  // the browser window and add it to the end of its tab list.
-  // Correctly, this registration should be called after this browser window
-  // receives a registered window message "TaskbarButtonCreated", which
-  // means that Windows creates a taskbar button for this window in its
-  // taskbar. But it seems to be OK to register it without checking the
-  // message.
-  // TODO(hbono): we need to check this registered message?
-  base::win::ScopedComPtr<ITaskbarList3> taskbar;
-  if (FAILED(taskbar.CreateInstance(CLSID_TaskbarList, NULL,
-                                    CLSCTX_INPROC_SERVER)) ||
-      FAILED(taskbar->HrInit()) ||
-      FAILED(taskbar->RegisterTab(window, frame_window)) ||
-      FAILED(taskbar->SetTabOrder(window, NULL)))
-    return;
-  if (active)
-    taskbar->SetTabActive(window, frame_window, 0);
-}
-
-// Calculates the thumbnail size sent to Windows so we can preserve the pixel
-// aspect-ratio of the source bitmap. Since Windows returns an error when we
-// send an image bigger than the given size, we decrease either the thumbnail
-// width or the thumbnail height so we can fit the longer edge of the source
-// window.
-void GetThumbnailSize(const gfx::Size& aeropeek_size, int width, int height,
-                      gfx::Size* output) {
-  float thumbnail_width = static_cast<float>(aeropeek_size.width());
-  float thumbnail_height = static_cast<float>(aeropeek_size.height());
-  float source_width = static_cast<float>(width);
-  float source_height = static_cast<float>(height);
-  DCHECK(source_width && source_height);
-
-  float ratio_width = thumbnail_width / source_width;
-  float ratio_height = thumbnail_height / source_height;
-  if (ratio_width > ratio_height) {
-    thumbnail_width = source_width * ratio_height;
-  } else {
-    thumbnail_height = source_height * ratio_width;
-  }
-
-  output->set_width(static_cast<int>(thumbnail_width));
-  output->set_height(static_cast<int>(thumbnail_height));
-}
-
-// Returns a pixel of the specified bitmap. If this bitmap is a dummy bitmap,
-// this function returns an opaque white pixel instead.
-int GetPixel(const SkBitmap& bitmap, int x, int y) {
-  const int* tab_pixels = reinterpret_cast<const int*>(bitmap.getPixels());
-  if (!tab_pixels)
-    return 0xFFFFFFFF;
-  return tab_pixels[y * bitmap.width() + x];
-}
-
-// A callback which creates a thumbnail image used by AeroPeek and sends it to
-// Windows.
-void SendThumbnailCallback(
-    HWND aeropeek_window, const gfx::Rect& content_bounds,
-    const gfx::Size& aeropeek_size, const SkBitmap& tab_bitmap,
-    base::WaitableEvent* ready) {
-  // Calculate the size of the aeropeek thumbnail and resize the tab bitmap
-  // to the size. When the given bitmap is an empty bitmap, we create a dummy
-  // bitmap from the content-area rectangle to create a DIB. (We don't need to
-  // allocate pixels for this case since we don't use them.)
-  gfx::Size thumbnail_size;
-  SkBitmap thumbnail_bitmap;
-
-  if (tab_bitmap.isNull() || tab_bitmap.empty()) {
-    GetThumbnailSize(
-        aeropeek_size, content_bounds.width(), content_bounds.height(),
-        &thumbnail_size);
-
-    thumbnail_bitmap.setConfig(SkBitmap::kARGB_8888_Config,
-                               thumbnail_size.width(), thumbnail_size.height());
-  } else {
-    GetThumbnailSize(aeropeek_size, tab_bitmap.width(), tab_bitmap.height(),
-                     &thumbnail_size);
-
-    thumbnail_bitmap = skia::ImageOperations::Resize(
-        tab_bitmap, skia::ImageOperations::RESIZE_LANCZOS3,
-        thumbnail_size.width(), thumbnail_size.height());
-  }
-
-  // Create a DIB, copy the resized image, and send the DIB to Windows.
-  // We can delete this DIB after sending it to Windows since Windows creates
-  // a copy of the DIB and use it.
-  base::win::ScopedCreateDC hdc(CreateCompatibleDC(NULL));
-  if (!hdc.Get()) {
-    LOG(ERROR) << "cannot create a memory DC: " << GetLastError();
-    return;
-  }
-
-  BITMAPINFOHEADER header;
-  gfx::CreateBitmapHeader(thumbnail_size.width(), thumbnail_size.height(),
-                          &header);
-
-  void* bitmap_data = NULL;
-  base::win::ScopedBitmap bitmap(
-      CreateDIBSection(hdc, reinterpret_cast<BITMAPINFO*>(&header),
-                       DIB_RGB_COLORS, &bitmap_data, NULL, 0));
-
-  if (!bitmap.Get() || !bitmap_data) {
-    LOG(ERROR) << "cannot create a bitmap: " << GetLastError();
-    return;
-  }
-
-  SkAutoLockPixels lock(thumbnail_bitmap);
-  int* content_pixels = reinterpret_cast<int*>(bitmap_data);
-  for (int y = 0; y < thumbnail_size.height(); ++y) {
-    for (int x = 0; x < thumbnail_size.width(); ++x) {
-      content_pixels[y * thumbnail_size.width() + x] =
-          GetPixel(thumbnail_bitmap, x, y);
-    }
-  }
-
-  HRESULT result = CallDwmSetIconicThumbnail(aeropeek_window, bitmap, 0);
-  if (FAILED(result))
-    LOG(ERROR) << "cannot set a tab thumbnail: " << result;
-
-  ready->Signal();
-}
-
-int GetTabPixel(const SkBitmap& tab_bitmap, int x, int y) {
-  // Return the opaque while pixel to prevent old foreground tab from being
-  // shown when we cannot get the specified pixel.
-  const int* tab_pixels = reinterpret_cast<int*>(tab_bitmap.getPixels());
-  if (!tab_pixels || x >= tab_bitmap.width() || y >= tab_bitmap.height())
-    return 0xFFFFFFFF;
-
-  // DWM uses alpha values to distinguish opaque colors and transparent ones.
-  // Set the alpha value of this source pixel to prevent the original window
-  // from being shown through.
-  return 0xFF000000 | tab_pixels[y * tab_bitmap.width() + x];
-}
-
-// A task which creates a preview image used by AeroPeek and sends it to
-// Windows.
-// This task becomes more complicated than SendThumbnailTask because this task
-// calculates the rectangle of the user-perceived content area (infobars +
-// content area) so Windows can paste the preview image on it.
-// This task is used if an AeroPeek window receives a
-// WM_DWMSENDICONICLIVEPREVIEWBITMAP message.
-void SendLivePreviewCallback(
-    HWND aeropeek_window, const gfx::Rect& content_bounds,
-    const SkBitmap& tab_bitmap) {
-  // Create a DIB for the user-perceived content area of the tab, copy the
-  // tab image into the DIB, and send it to Windows.
-  // We don't need to paste this tab image onto the frame image since Windows
-  // automatically pastes it for us.
-  base::win::ScopedCreateDC hdc(CreateCompatibleDC(NULL));
-  if (!hdc.Get()) {
-    LOG(ERROR) << "cannot create a memory DC: " << GetLastError();
-    return;
-  }
-
-  BITMAPINFOHEADER header;
-  gfx::CreateBitmapHeader(content_bounds.width(), content_bounds.height(),
-                          &header);
-
-  void* bitmap_data = NULL;
-  base::win::ScopedBitmap bitmap(
-      CreateDIBSection(hdc.Get(), reinterpret_cast<BITMAPINFO*>(&header),
-                       DIB_RGB_COLORS, &bitmap_data, NULL, 0));
-  if (!bitmap.Get() || !bitmap_data) {
-    LOG(ERROR) << "cannot create a bitmap: " << GetLastError();
-    return;
-  }
-
-  // Copy the tab image onto the DIB.
-  SkAutoLockPixels lock(tab_bitmap);
-  int* content_pixels = reinterpret_cast<int*>(bitmap_data);
-  for (int y = 0; y < content_bounds.height(); ++y) {
-    for (int x = 0; x < content_bounds.width(); ++x)
-      content_pixels[y * content_bounds.width() + x] =
-          GetTabPixel(tab_bitmap, x, y);
-  }
-
-  // Send the preview image to Windows.
-  // We can set its offset to the top left corner of the user-perceived
-  // content area so Windows can paste this bitmap onto the correct
-  // position.
-  POINT content_offset = {content_bounds.x(), content_bounds.y()};
-  HRESULT result = CallDwmSetIconicLivePreviewBitmap(
-      aeropeek_window, bitmap, &content_offset, 0);
-  if (FAILED(result))
-    LOG(ERROR) << "cannot send a content image: " << result;
-}
-
-}  // namespace
-
-// A class which implements a place-holder window used by AeroPeek.
-// The major work of this class are:
-// * Updating the status of Tab Thumbnails;
-// * Receiving messages from Windows, and;
-// * Translating received messages for TabStrip.
-// This class is used by the AeroPeekManager class, which is a proxy
-// between TabStrip and Windows 7.
-class AeroPeekWindow : public ui::WindowImpl {
- public:
-  AeroPeekWindow(HWND frame_window,
-                 AeroPeekWindowDelegate* delegate,
-                 int tab_id,
-                 bool tab_active,
-                 const std::wstring& title,
-                 const SkBitmap& favicon_bitmap);
-  ~AeroPeekWindow();
-
-  // Activates or deactivates this window.
-  // This window uses this information not only for highlighting the selected
-  // tab when Windows shows the thumbnail list, but also for preventing us
-  // from rendering AeroPeek images for deactivated windows so often.
-  void Activate();
-  void Deactivate();
-
-  // Updates the image of this window.
-  // When the AeroPeekManager class calls this function, this window starts
-  // a task which updates its thumbnail image.
-  // NOTE: to prevent sending lots of tasks that update the thumbnail images
-  // and hurt the system performance, we post a task only when |is_loading| is
-  // false for non-active tabs. (On the other hand, we always post an update
-  // task for an active tab as IE8 does.)
-  void Update(bool is_loading);
-
-  // Destroys this window.
-  // This function removes this window from the thumbnail list and deletes
-  // all the resources attached to this window, i.e. this object is not valid
-  // any longer after calling this function.
-  void Destroy();
-
-  // Updates the title of this window.
-  // This function just sends a WM_SETTEXT message to update the window title.
-  void SetTitle(const std::wstring& title);
-
-  // Updates the icon used for AeroPeek. Unlike SetTitle(), this function just
-  // saves a copy of the given bitmap since it takes time to create a Windows
-  // icon from this bitmap set it as the window icon. We will create a Windows
-  // when Windows sends a WM_GETICON message to retrieve it.
-  void SetFavicon(const SkBitmap& favicon);
-
-  // Returns the tab ID associated with this window.
-  int tab_id() { return tab_id_; }
-
-  // Message handlers.
-  BEGIN_MSG_MAP_EX(TabbedThumbnailWindow)
-    MESSAGE_HANDLER_EX(WM_DWMSENDICONICTHUMBNAIL, OnDwmSendIconicThumbnail)
-    MESSAGE_HANDLER_EX(WM_DWMSENDICONICLIVEPREVIEWBITMAP,
-                       OnDwmSendIconicLivePreviewBitmap)
-
-    MSG_WM_ACTIVATE(OnActivate)
-    MSG_WM_CLOSE(OnClose)
-    MSG_WM_CREATE(OnCreate)
-    MSG_WM_GETICON(OnGetIcon)
-  END_MSG_MAP()
-
- private:
-  // Updates the thumbnail image of this window.
-  // This function is a wrapper function of CallDwmInvalidateIconicBitmaps()
-  // but it invalidates the thumbnail only when |ready_| is signaled to prevent
-  // us from posting two or more tasks.
-  void UpdateThumbnail();
-
-  // Returns the user-perceived content area.
-  gfx::Rect GetContentBounds() const;
-
-  // Message-handler functions.
-  // Called when a window has been created.
-  LRESULT OnCreate(LPCREATESTRUCT create_struct);
-
-  // Called when this thumbnail window is activated, i.e. a user clicks this
-  // thumbnail window.
-  void OnActivate(UINT action, BOOL minimized, HWND window);
-
-  // Called when this thumbnail window is closed, i.e. a user clicks the close
-  // button of this thumbnail window.
-  void OnClose();
-
-  // Called when Windows needs a thumbnail image for this thumbnail window.
-  // Windows can send a WM_DWMSENDICONICTHUMBNAIL message anytime when it
-  // needs the thumbnail bitmap for this place-holder window (e.g. when we
-  // register this place-holder window to Windows, etc.)
-  // When this window receives a WM_DWMSENDICONICTHUMBNAIL message, it HAS TO
-  // create a thumbnail bitmap and send it to Windows through a
-  // DwmSendIconicThumbnail() call. (Windows shows a "page-loading" animation
-  // while it waits for a thumbnail bitmap.)
-  LRESULT OnDwmSendIconicThumbnail(UINT message,
-                                   WPARAM wparam,
-                                   LPARAM lparam);
-
-  // Called when Windows needs a preview image for this thumbnail window.
-  // Same as above, Windows can send a WM_DWMSENDICONICLIVEPREVIEWBITMAP
-  // message anytime when it needs a preview bitmap and we have to create and
-  // send the bitmap when it needs it.
-  LRESULT OnDwmSendIconicLivePreviewBitmap(UINT message,
-                                           WPARAM wparam,
-                                           LPARAM lparam);
-
-  // Called when Windows needs an icon for this thumbnail window.
-  // Windows sends a WM_GETICON message with ICON_SMALL when it needs an
-  // AeroPeek icon. we handle WM_GETICON messages by ourselves so we can create
-  // a custom icon from a favicon only when Windows need it.
-  HICON OnGetIcon(UINT index);
-
- private:
-  // An application window which owns this tab.
-  // We show this thumbnail image of this window when a user hovers a mouse
-  // cursor onto the taskbar icon of this application window.
-  HWND frame_window_;
-
-  // An interface which dispatches events received from Window.
-  // This window notifies events received from Windows to TabStrip through
-  // this interface.
-  // We should not directly access WebContents members since Windows may send
-  // AeroPeek events to a tab closed by Chrome.
-  // To prevent such race condition, we get access to WebContents through
-  // AeroPeekManager.
-  AeroPeekWindowDelegate* delegate_;
-
-  // A tab ID associated with this window.
-  int tab_id_;
-
-  // A flag that represents whether or not this tab is active.
-  // This flag is used for preventing us from updating the thumbnail images
-  // when this window is not active.
-  bool tab_active_;
-
-  // An event that represents whether or not we can post a task which updates
-  // the thumbnail image of this window.
-  // We post a task only when this event is signaled.
-  base::WaitableEvent ready_to_update_thumbnail_;
-
-  // The title of this tab.
-  std::wstring title_;
-
-  // The favicon for this tab.
-  SkBitmap favicon_bitmap_;
-  base::win::ScopedHICON favicon_;
-
-  // The icon used by the frame window.
-  // This icon is used when this tab doesn't have a favicon.
-  HICON frame_icon_;
-
-  DISALLOW_COPY_AND_ASSIGN(AeroPeekWindow);
-};
-
-AeroPeekWindow::AeroPeekWindow(HWND frame_window,
-                               AeroPeekWindowDelegate* delegate,
-                               int tab_id,
-                               bool tab_active,
-                               const std::wstring& title,
-                               const SkBitmap& favicon_bitmap)
-    : frame_window_(frame_window),
-      delegate_(delegate),
-      tab_id_(tab_id),
-      tab_active_(tab_active),
-      ready_to_update_thumbnail_(false, true),
-      title_(title),
-      favicon_bitmap_(favicon_bitmap),
-      frame_icon_(NULL) {
-  // Set the class styles and window styles for this thumbnail window.
-  // An AeroPeek window should be a tool window. (Otherwise,
-  // Windows doesn't send WM_DWMSENDICONICTHUMBNAIL messages.)
-  set_initial_class_style(0);
-  set_window_style(WS_POPUP | WS_BORDER | WS_SYSMENU | WS_CAPTION);
-  set_window_ex_style(WS_EX_TOOLWINDOW | WS_EX_NOACTIVATE);
-}
-
-AeroPeekWindow::~AeroPeekWindow() {
-}
-
-void AeroPeekWindow::Activate() {
-  tab_active_ = true;
-
-  // Create a place-holder window and add it to the tab list if it has not been
-  // created yet. (This case happens when we re-attached a detached window.)
-  if (!IsWindow(hwnd())) {
-    Update(false);
-    return;
-  }
-
-  // Notify Windows to set the thumbnail focus to this window.
-  base::win::ScopedComPtr<ITaskbarList3> taskbar;
-  HRESULT result = taskbar.CreateInstance(CLSID_TaskbarList, NULL,
-                                          CLSCTX_INPROC_SERVER);
-  if (FAILED(result)) {
-    LOG(ERROR) << "failed creating an ITaskbarList3 interface.";
-    return;
-  }
-
-  result = taskbar->HrInit();
-  if (FAILED(result)) {
-    LOG(ERROR) << "failed initializing an ITaskbarList3 interface.";
-    return;
-  }
-
-  result = taskbar->ActivateTab(hwnd());
-  if (FAILED(result)) {
-    LOG(ERROR) << "failed activating a thumbnail window.";
-    return;
-  }
-
-  // Update the thumbnail image to the up-to-date one.
-  UpdateThumbnail();
-}
-
-void AeroPeekWindow::Deactivate() {
-  tab_active_ = false;
-}
-
-void AeroPeekWindow::Update(bool is_loading) {
-  // Create a place-holder window used by AeroPeek if it has not been created
-  // so Windows can send events used by AeroPeek to this window.
-  // Windows automatically sends a WM_DWMSENDICONICTHUMBNAIL message after this
-  // window is registered to Windows. So, we don't have to invalidate the
-  // thumbnail image of this window now.
-  if (!hwnd()) {
-    gfx::Rect bounds;
-    WindowImpl::Init(frame_window_, bounds);
-    return;
-  }
-
-  // Invalidate the thumbnail image of this window.
-  // When we invalidate the thumbnail image, we HAVE TO handle a succeeding
-  // WM_DWMSENDICONICTHUMBNAIL message and update the thumbnail image with a
-  // DwmSetIconicThumbnail() call. So, we should not call this function when
-  // we don't have enough information to create a thumbnail.
-  if (tab_active_ || !is_loading)
-    UpdateThumbnail();
-}
-
-void AeroPeekWindow::Destroy() {
-  if (!IsWindow(hwnd()))
-    return;
-
-  // Remove this window from the tab list of Windows.
-  base::win::ScopedComPtr<ITaskbarList3> taskbar;
-  HRESULT result = taskbar.CreateInstance(CLSID_TaskbarList, NULL,
-                                          CLSCTX_INPROC_SERVER);
-  if (FAILED(result))
-    return;
-
-  result = taskbar->HrInit();
-  if (FAILED(result))
-    return;
-
-  result = taskbar->UnregisterTab(hwnd());
-
-  // Destroy this window.
-  DestroyWindow(hwnd());
-}
-
-void AeroPeekWindow::SetTitle(const std::wstring& title) {
-  title_ = title;
-}
-
-void AeroPeekWindow::SetFavicon(const SkBitmap& favicon) {
-  favicon_bitmap_ = favicon;
-}
-
-void AeroPeekWindow::UpdateThumbnail() {
-  // We post a task to actually create a new thumbnail. So, this function may
-  // be called while we are creating a thumbnail. To prevent this window from
-  // posting two or more tasks, we don't invalidate the current thumbnail
-  // when this event is not signaled.
-  if (ready_to_update_thumbnail_.IsSignaled())
-    CallDwmInvalidateIconicBitmaps(hwnd());
-}
-
-gfx::Rect AeroPeekWindow::GetContentBounds() const {
-  RECT content_rect;
-  GetClientRect(frame_window_, &content_rect);
-
-  gfx::Insets content_insets;
-  delegate_->GetContentInsets(&content_insets);
-
-  gfx::Rect content_bounds(content_rect);
-  content_bounds.Inset(content_insets.left(),
-                       content_insets.top(),
-                       content_insets.right(),
-                       content_insets.bottom());
-  return content_bounds;
-}
-
-// message handlers
-
-void AeroPeekWindow::OnActivate(UINT action,
-                                BOOL minimized,
-                                HWND window) {
-  // Windows sends a WM_ACTIVATE message not only when a user clicks this
-  // window (i.e. this window gains the thumbnail focus) but also a user clicks
-  // another window (i.e. this window loses the thumbnail focus.)
-  // Return when this window loses the thumbnail focus since we don't have to
-  // do anything for this case.
-  if (action == WA_INACTIVE)
-    return;
-
-  // Ask Chrome to activate the tab associated with this thumbnail window.
-  // Since TabStripModel calls AeroPeekManager::ActiveTabChanged() when it
-  // finishes activating the tab. We will move the tab focus of AeroPeek there.
-  if (delegate_)
-    delegate_->ActivateTab(tab_id_);
-}
-
-LRESULT AeroPeekWindow::OnCreate(LPCREATESTRUCT create_struct) {
-  // Initialize the window title now since WindowImpl::Init() always calls
-  // CreateWindowEx() with its window name NULL.
-  if (!title_.empty()) {
-    SendMessage(hwnd(), WM_SETTEXT, 0,
-                reinterpret_cast<LPARAM>(title_.c_str()));
-  }
-
-  // Window attributes for DwmSetWindowAttribute().
-  // These enum values are copied from Windows SDK 7 so we can compile this
-  // file with or without it.
-  // TODO(hbono): Bug 16903: to be deleted when we use Windows SDK 7.
-  enum {
-    DWMWA_NCRENDERING_ENABLED = 1,
-    DWMWA_NCRENDERING_POLICY,
-    DWMWA_TRANSITIONS_FORCEDISABLED,
-    DWMWA_ALLOW_NCPAINT,
-    DWMWA_CAPTION_BUTTON_BOUNDS,
-    DWMWA_NONCLIENT_RTL_LAYOUT,
-    DWMWA_FORCE_ICONIC_REPRESENTATION,
-    DWMWA_FLIP3D_POLICY,
-    DWMWA_EXTENDED_FRAME_BOUNDS,
-    DWMWA_HAS_ICONIC_BITMAP,
-    DWMWA_DISALLOW_PEEK,
-    DWMWA_EXCLUDED_FROM_PEEK,
-    DWMWA_LAST
-  };
-
-  // Set DWM attributes to tell Windows that this window can provide the
-  // bitmaps used by AeroPeek.
-  BOOL force_iconic_representation = TRUE;
-  DwmSetWindowAttribute(hwnd(),
-                        DWMWA_FORCE_ICONIC_REPRESENTATION,
-                        &force_iconic_representation,
-                        sizeof(force_iconic_representation));
-
-  BOOL has_iconic_bitmap = TRUE;
-  DwmSetWindowAttribute(hwnd(),
-                        DWMWA_HAS_ICONIC_BITMAP,
-                        &has_iconic_bitmap,
-                        sizeof(has_iconic_bitmap));
-
-  // Post a task that registers this thumbnail window to Windows because it
-  // may take some time. (For example, when we create an ITaskbarList3
-  // interface for the first time, Windows loads DLLs and we need to wait for
-  // some time.)
-  BrowserThread::PostTask(
-      BrowserThread::IO, FROM_HERE,
-      base::Bind(&RegisterThumbnailCallback, frame_window_, hwnd(),
-                 tab_active_));
-
-  return 0;
-}
-
-void AeroPeekWindow::OnClose() {
-  // Unregister this window from the tab list of Windows and destroy this
-  // window.
-  // The resources attached to this object will be deleted when TabStrip calls
-  // AeroPeekManager::TabClosingAt(). (Please read the comment in TabClosingAt()
-  // for its details.)
-  Destroy();
-
-  // Ask AeroPeekManager to close the tab associated with this thumbnail
-  // window.
-  if (delegate_)
-    delegate_->CloseTab(tab_id_);
-}
-
-LRESULT AeroPeekWindow::OnDwmSendIconicThumbnail(UINT message,
-                                                 WPARAM wparam,
-                                                 LPARAM lparam) {
-  // Update the window title to synchronize the title.
-  SendMessage(hwnd(), WM_SETTEXT, 0, reinterpret_cast<LPARAM>(title_.c_str()));
-
-  // Create an I/O task since it takes long time to resize these images and
-  // send them to Windows. This task signals |ready_to_update_thumbnail_| in
-  // its destructor to notify us when this task has been finished. (We create an
-  // I/O task even when the given thumbnail is empty to stop the "loading"
-  // animation.)
-  DCHECK(delegate_);
-
-  SkBitmap thumbnail;
-  delegate_->GetTabThumbnail(tab_id_, &thumbnail);
-
-  gfx::Size aeropeek_size(HIWORD(lparam), LOWORD(lparam));
-  BrowserThread::PostTask(
-      BrowserThread::IO, FROM_HERE,
-      base::Bind(&SendThumbnailCallback, hwnd(), GetContentBounds(),
-                 aeropeek_size, thumbnail, &ready_to_update_thumbnail_));
-  return 0;
-}
-
-LRESULT AeroPeekWindow::OnDwmSendIconicLivePreviewBitmap(UINT message,
-                                                         WPARAM wparam,
-                                                         LPARAM lparam) {
-  // Same as OnDwmSendIconicThumbnail(), we create an I/O task which creates
-  // a preview image used by AeroPeek and send it to Windows. Unlike
-  // OnDwmSendIconicThumbnail(), we don't have to use events for preventing this
-  // window from sending two or more tasks because Windows doesn't send
-  // WM_DWMSENDICONICLIVEPREVIEWBITMAP messages before we send the preview image
-  // to Windows.
-  DCHECK(delegate_);
-
-  SkBitmap preview;
-  delegate_->GetTabPreview(tab_id_, &preview);
-
-  BrowserThread::PostTask(
-      BrowserThread::IO, FROM_HERE,
-      base::Bind(&SendLivePreviewCallback, hwnd(), GetContentBounds(),
-                 preview));
-
-  return 0;
-}
-
-HICON AeroPeekWindow::OnGetIcon(UINT index) {
-  // Return the application icon if this window doesn't have favicons.
-  // We save this application icon to avoid calling LoadIcon() twice or more.
-  if (favicon_bitmap_.isNull()) {
-    if (!frame_icon_) {
-      frame_icon_ = GetAppIcon();
-    }
-    return frame_icon_;
-  }
-
-  // Create a Windows icon from SkBitmap and send it to Windows. We set this
-  // icon to the ScopedIcon object to delete it in the destructor.
-  favicon_.Set(IconUtil::CreateHICONFromSkBitmap(favicon_bitmap_));
-  return favicon_.Get();
-}
-
-AeroPeekManager::AeroPeekManager(HWND application_window)
-    : application_window_(application_window),
-      border_left_(0),
-      border_top_(0),
-      toolbar_top_(0) {
-}
-
-AeroPeekManager::~AeroPeekManager() {
-  // Delete all AeroPeekWindow objects.
-  for (std::list<AeroPeekWindow*>::iterator i = tab_list_.begin();
-       i != tab_list_.end(); ++i) {
-    AeroPeekWindow* window = *i;
-    delete window;
-  }
-}
-
-void AeroPeekManager::SetContentInsets(const gfx::Insets& insets) {
-  content_insets_ = insets;
-}
-
-// static
-bool AeroPeekManager::Enabled() {
-  // We enable our custom AeroPeek only when:
-  // * Chrome is running on Windows 7 and Aero is enabled,
-  // * Chrome is not launched in application mode, and
-  // * Chrome is launched with the "--enable-aero-peek-tabs" option.
-  // TODO(hbono): Bug 37957 <http://crbug.com/37957>: find solutions that avoid
-  // flooding users with tab thumbnails.
-  const CommandLine* command_line = CommandLine::ForCurrentProcess();
-  return base::win::GetVersion() >= base::win::VERSION_WIN7 &&
-      views::NativeWidgetWin::IsAeroGlassEnabled() &&
-      !command_line->HasSwitch(switches::kApp) &&
-      command_line->HasSwitch(switches::kEnableAeroPeekTabs);
-}
-
-void AeroPeekManager::DeleteAeroPeekWindow(int tab_id) {
-  // This function does NOT call AeroPeekWindow::Destroy() before deleting
-  // the AeroPeekWindow instance.
-  for (std::list<AeroPeekWindow*>::iterator i = tab_list_.begin();
-       i != tab_list_.end(); ++i) {
-    AeroPeekWindow* window = *i;
-    if (window->tab_id() == tab_id) {
-      tab_list_.erase(i);
-      delete window;
-      return;
-    }
-  }
-}
-
-void AeroPeekManager::DeleteAeroPeekWindowForTab(TabContentsWrapper* tab) {
-  // Delete the AeroPeekWindow object associated with this tab and all its
-  // resources. (AeroPeekWindow::Destory() also removes this tab from the tab
-  // list of Windows.)
-  AeroPeekWindow* window = GetAeroPeekWindow(GetTabID(tab));
-  if (!window)
-    return;
-
-  window->Destroy();
-  DeleteAeroPeekWindow(GetTabID(tab));
-}
-
-AeroPeekWindow* AeroPeekManager::GetAeroPeekWindow(int tab_id) const {
-  size_t size = tab_list_.size();
-  for (std::list<AeroPeekWindow*>::const_iterator i = tab_list_.begin();
-       i != tab_list_.end(); ++i) {
-    AeroPeekWindow* window = *i;
-    if (window->tab_id() == tab_id)
-      return window;
-  }
-  return NULL;
-}
-
-void AeroPeekManager::CreateAeroPeekWindowIfNecessary(TabContentsWrapper* tab,
-                                                      bool foreground) {
-  if (GetAeroPeekWindow(GetTabID(tab)))
-    return;
-
-  AeroPeekWindow* window =
-      new AeroPeekWindow(application_window_,
-                         this,
-                         GetTabID(tab),
-                         foreground,
-                         tab->web_contents()->GetTitle(),
-                         tab->favicon_tab_helper()->GetFavicon());
-  tab_list_.push_back(window);
-}
-
-WebContents* AeroPeekManager::GetWebContents(int tab_id) const {
-  for (TabContentsIterator iterator; !iterator.done(); ++iterator) {
-    if (GetTabID(*iterator) == tab_id)
-      return (*iterator)->web_contents();
-  }
-  return NULL;
-}
-
-int AeroPeekManager::GetTabID(TabContentsWrapper* contents) const {
-  if (!contents)
-    return -1;
-  return contents->restore_tab_helper()->session_id().id();
-}
-
-///////////////////////////////////////////////////////////////////////////////
-// AeroPeekManager, TabStripModelObserver implementation:
-
-void AeroPeekManager::TabInsertedAt(TabContentsWrapper* contents,
-                                    int index,
-                                    bool foreground) {
-  if (!contents)
-    return;
-
-  CreateAeroPeekWindowIfNecessary(contents, foreground);
-}
-
-void AeroPeekManager::TabDetachedAt(TabContentsWrapper* contents, int index) {
-  if (!contents)
-    return;
-
-  // Chrome will call TabInsertedAt() when this tab is inserted to another
-  // TabStrip. We will re-create an AeroPeekWindow object for this tab and
-  // re-add it to the tab list there.
-  DeleteAeroPeekWindowForTab(contents);
-}
-
-void AeroPeekManager::ActiveTabChanged(TabContentsWrapper* old_contents,
-                                       TabContentsWrapper* new_contents,
-                                       int index,
-                                       bool user_gesture) {
-  // Deactivate the old window in the thumbnail list and activate the new one
-  // to synchronize the thumbnail list with TabStrip.
-  if (old_contents) {
-    AeroPeekWindow* old_window = GetAeroPeekWindow(GetTabID(old_contents));
-    if (old_window)
-      old_window->Deactivate();
-  }
-
-  if (new_contents) {
-    AeroPeekWindow* new_window = GetAeroPeekWindow(GetTabID(new_contents));
-    if (new_window)
-      new_window->Activate();
-  }
-}
-
-void AeroPeekManager::TabReplacedAt(TabStripModel* tab_strip_model,
-                                    TabContentsWrapper* old_contents,
-                                    TabContentsWrapper* new_contents,
-                                    int index) {
-  DeleteAeroPeekWindowForTab(old_contents);
-
-  CreateAeroPeekWindowIfNecessary(new_contents,
-                                  (index == tab_strip_model->active_index()));
-  // We don't need to update the selection as if |new_contents| is selected the
-  // TabStripModel will send ActiveTabChanged.
-}
-
-void AeroPeekManager::TabMoved(TabContentsWrapper* contents,
-                               int from_index,
-                               int to_index,
-                               bool pinned_state_changed) {
-  // TODO(hbono): we need to reorder the thumbnail list of Windows here?
-  // (Unfortunately, it is not so trivial to reorder the thumbnail list when
-  // we detach/attach tabs.)
-}
-
-void AeroPeekManager::TabChangedAt(TabContentsWrapper* contents,
-                                   int index,
-                                   TabChangeType change_type) {
-  if (!contents)
-    return;
-
-  // Retrieve the AeroPeekWindow object associated with this tab, update its
-  // title, and post a task that update its thumbnail image if necessary.
-  AeroPeekWindow* window = GetAeroPeekWindow(GetTabID(contents));
-  if (!window)
-    return;
-
-  // Update the title, the favicon, and the thumbnail used for AeroPeek.
-  // These function don't actually update the icon and the thumbnail until
-  // Windows needs them (e.g. when a user hovers a taskbar icon) to avoid
-  // hurting the rendering performance. (These functions just save the
-  // information needed for handling update requests from Windows.)
-  window->SetTitle(contents->web_contents()->GetTitle());
-  window->SetFavicon(contents->favicon_tab_helper()->GetFavicon());
-  window->Update(contents->web_contents()->IsLoading());
-}
-
-///////////////////////////////////////////////////////////////////////////////
-// AeroPeekManager, AeroPeekWindowDelegate implementation:
-
-void AeroPeekManager::ActivateTab(int tab_id) {
-  // Ask TabStrip to activate this tab.
-  // We don't have to update thumbnails now since TabStrip will call
-  // ActiveTabChanged() when it actually activates this tab.
-  WebContents* contents = GetWebContents(tab_id);
-  if (contents && contents->GetDelegate())
-    contents->GetDelegate()->ActivateContents(contents);
-}
-
-void AeroPeekManager::CloseTab(int tab_id) {
-  // Ask TabStrip to close this tab.
-  // TabStrip will call TabClosingAt() when it actually closes this tab. We
-  // will delete the AeroPeekWindow object attached to this tab there.
-  WebContents* contents = GetWebContents(tab_id);
-  if (contents && contents->GetDelegate())
-    contents->GetDelegate()->CloseContents(contents);
-}
-
-void AeroPeekManager::GetContentInsets(gfx::Insets* insets) {
-  *insets = content_insets_;
-}
-
-bool AeroPeekManager::GetTabThumbnail(int tab_id, SkBitmap* thumbnail) {
-  DCHECK(thumbnail);
-
-  // Copy the thumbnail image and the favicon of this tab. We will resize the
-  // images and send them to Windows.
-  WebContents* contents = GetWebContents(tab_id);
-  if (!contents)
-    return false;
-
-  ThumbnailGenerator* generator = g_browser_process->GetThumbnailGenerator();
-  DCHECK(generator);
-  *thumbnail = generator->GetThumbnailForRenderer(
-      contents->GetRenderViewHost());
-
-  return true;
-}
-
-bool AeroPeekManager::GetTabPreview(int tab_id, SkBitmap* preview) {
-  DCHECK(preview);
-
-  // Retrieve the BackingStore associated with the given tab and return its
-  // SkPlatformCanvas.
-  WebContents* contents = GetWebContents(tab_id);
-  if (!contents)
-    return false;
-
-  content::RenderViewHost* render_view_host = contents->GetRenderViewHost();
-  if (!render_view_host)
-    return false;
-  content::RenderWidgetHostView* view = render_view_host->GetView();
-  if (!view)
-    return false;
-
-  // Create a copy of this BackingStore image.
-  // This code is just copied from "thumbnail_generator.cc".
-  skia::PlatformCanvas canvas;
-  bool result = false;
-  bool done = false;
-  render_view_host->AsyncCopyFromBackingStore(
-      gfx::Rect(),
-      view->GetViewBounds().size(),
-      &canvas,
-      base::Bind(&CopyFromBackingStoreComplete,
-                 &result,
-                 &done));
-  // RenderWidgetHost::AyncCopyFromBackingStore is currently implemented to run
-  // synchronously.
-  // TODO(mazda): Fix this so that it does not need to be synchronous
-  // (http://crbug.com/126203).
-  DCHECK(done);
-  if (!result)
-    return false;
-
-  const SkBitmap& bitmap = skia::GetTopDevice(canvas)->accessBitmap(false);
-  bitmap.copyTo(preview, SkBitmap::kARGB_8888_Config);
-  return true;
-}