Remove Tabpose feature on mac, and supporting infrastructure (PaintAtSize)

chrome/browser/ui/cocoa/tabpose_window.mm

Index: chrome/browser/ui/cocoa/tabpose_window.mm
diff --git a/chrome/browser/ui/cocoa/tabpose_window.mm b/chrome/browser/ui/cocoa/tabpose_window.mm
deleted file mode 100644
index f4cc4fc25ae857e0054a90dcc4494e301a1ff6ce..0000000000000000000000000000000000000000
--- a/chrome/browser/ui/cocoa/tabpose_window.mm
+++ /dev/null
@@ -1,1664 +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.
-
-#import "chrome/browser/ui/cocoa/tabpose_window.h"
-
-#import <QuartzCore/QuartzCore.h>
-
-#include <algorithm>
-
-#include "base/mac/mac_util.h"
-#include "base/mac/scoped_cftyperef.h"
-#include "base/memory/weak_ptr.h"
-#include "base/prefs/pref_service.h"
-#include "base/strings/sys_string_conversions.h"
-#include "chrome/app/chrome_command_ids.h"
-#include "chrome/browser/browser_process.h"
-#include "chrome/browser/devtools/devtools_window.h"
-#include "chrome/browser/extensions/tab_helper.h"
-#include "chrome/browser/profiles/profile.h"
-#include "chrome/browser/thumbnails/render_widget_snapshot_taker.h"
-#include "chrome/browser/ui/bookmarks/bookmark_tab_helper.h"
-#import "chrome/browser/ui/cocoa/bookmarks/bookmark_bar_constants.h"
-#import "chrome/browser/ui/cocoa/browser_window_controller.h"
-#import "chrome/browser/ui/cocoa/infobars/infobar_container_controller.h"
-#import "chrome/browser/ui/cocoa/tab_contents/favicon_util_mac.h"
-#import "chrome/browser/ui/cocoa/tabs/tab_strip_controller.h"
-#import "chrome/browser/ui/cocoa/tabs/tab_strip_model_observer_bridge.h"
-#include "chrome/common/pref_names.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_view.h"
-#include "grit/theme_resources.h"
-#include "grit/ui_resources.h"
-#include "skia/ext/skia_utils_mac.h"
-#include "third_party/skia/include/utils/mac/SkCGUtils.h"
-#include "ui/base/cocoa/animation_utils.h"
-#include "ui/base/resource/resource_bundle.h"
-#include "ui/gfx/image/image.h"
-#include "ui/gfx/scoped_cg_context_save_gstate_mac.h"
-
-using content::BrowserThread;
-using content::RenderWidgetHost;
-
-// Height of the bottom gradient, in pixels.
-const CGFloat kBottomGradientHeight = 50;
-
-// The shade of gray at the top of the window. There's a  gradient from
-// this to |kCentralGray| at the top of the window.
-const CGFloat kTopGray = 0.77;
-
-// The shade of gray at the center of the window. Most of the window background
-// has this color.
-const CGFloat kCentralGray = 0.6;
-
-// The shade of gray at the bottom of the window. There's a gradient from
-// |kCentralGray| to this at the bottom of the window, |kBottomGradientHeight|
-// high.
-const CGFloat kBottomGray = 0.5;
-
-NSString* const kAnimationIdKey = @"AnimationId";
-NSString* const kAnimationIdFadeIn = @"FadeIn";
-NSString* const kAnimationIdFadeOut = @"FadeOut";
-
-const CGFloat kDefaultAnimationDuration = 0.25;  // In seconds.
-const CGFloat kSlomoFactor = 4;
-const CGFloat kObserverChangeAnimationDuration = 0.25;  // In seconds.
-const CGFloat kSelectionInset = 5;
-
-// CAGradientLayer is 10.6-only -- roll our own.
-@interface GrayGradientLayer : CALayer {
- @private
-  CGFloat startGray_;
-  CGFloat endGray_;
-}
-- (id)initWithStartGray:(CGFloat)startGray endGray:(CGFloat)endGray;
-- (void)drawInContext:(CGContextRef)context;
-@end
-
-@implementation GrayGradientLayer
-- (id)initWithStartGray:(CGFloat)startGray endGray:(CGFloat)endGray {
-  if ((self = [super init])) {
-    startGray_ = startGray;
-    endGray_ = endGray;
-  }
-  return self;
-}
-
-- (void)drawInContext:(CGContextRef)context {
-  base::ScopedCFTypeRef<CGColorSpaceRef> grayColorSpace(
-      CGColorSpaceCreateWithName(kCGColorSpaceGenericGray));
-  CGFloat grays[] = { startGray_, 1.0, endGray_, 1.0 };
-  CGFloat locations[] = { 0, 1 };
-  base::ScopedCFTypeRef<CGGradientRef> gradient(
-      CGGradientCreateWithColorComponents(
-          grayColorSpace.get(), grays, locations, arraysize(locations)));
-  CGPoint topLeft = CGPointMake(0.0, self.bounds.size.height);
-  CGContextDrawLinearGradient(context, gradient.get(), topLeft, CGPointZero, 0);
-}
-@end
-
-namespace tabpose {
-class ThumbnailLoader;
-}
-
-// A CALayer that draws a thumbnail for a WebContents object. The layer
-// tries to draw the WebContents's backing store directly if possible, and
-// requests a thumbnail bitmap from the WebContents's renderer process if not.
-@interface ThumbnailLayer : CALayer {
-  // The WebContents the thumbnail is for.
-  content::WebContents* contents_;  // weak
-
-  // The size the thumbnail is drawn at when zoomed in.
-  NSSize fullSize_;
-
-  // Used to load a thumbnail, if required.
-  scoped_refptr<tabpose::ThumbnailLoader> loader_;
-
-  // If the backing store couldn't be used and a thumbnail was returned from a
-  // renderer process, it's stored in |thumbnail_|.
-  base::ScopedCFTypeRef<CGImageRef> thumbnail_;
-
-  // True if the layer already sent a thumbnail request to a renderer.
-  BOOL didSendLoad_;
-}
-- (id)initWithWebContents:(content::WebContents*)contents
-                 fullSize:(NSSize)fullSize;
-- (void)drawInContext:(CGContextRef)context;
-- (void)setThumbnail:(const SkBitmap&)bitmap;
-@end
-
-namespace tabpose {
-
-// ThumbnailLoader talks to the renderer process to load a thumbnail of a given
-// RenderWidgetHost, and sends the thumbnail back to a ThumbnailLayer once it
-// comes back from the renderer.
-class ThumbnailLoader : public base::RefCountedThreadSafe<ThumbnailLoader> {
- public:
-  ThumbnailLoader(gfx::Size size, RenderWidgetHost* rwh, ThumbnailLayer* layer)
-      : size_(size), rwh_(rwh), layer_(layer), weak_factory_(this) {}
-
-  // Starts the fetch.
-  void LoadThumbnail();
-
- private:
-  friend class base::RefCountedThreadSafe<ThumbnailLoader>;
-  ~ThumbnailLoader() {
-  }
-
-  void DidReceiveBitmap(const SkBitmap& bitmap) {
-    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-    [layer_ setThumbnail:bitmap];
-  }
-
-  gfx::Size size_;
-  RenderWidgetHost* rwh_;  // weak
-  ThumbnailLayer* layer_;  // weak, owns us
-  base::WeakPtrFactory<ThumbnailLoader> weak_factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(ThumbnailLoader);
-};
-
-void ThumbnailLoader::LoadThumbnail() {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-
-  // As mentioned in ThumbnailLayer's -drawInContext:, it's sufficient to have
-  // thumbnails at the zoomed-out pixel size for all but the thumbnail the user
-  // clicks on in the end. But we don't don't which thumbnail that will be, so
-  // keep it simple and request full thumbnails for everything.
-  // TODO(thakis): Request smaller thumbnails for users with many tabs.
-  gfx::Size page_size(size_);  // Logical size the renderer renders at.
-  gfx::Size pixel_size(size_);  // Physical pixel size the image is rendered at.
-
-  // Will send an IPC to the renderer on the IO thread.
-  g_browser_process->GetRenderWidgetSnapshotTaker()->AskForSnapshot(
-      rwh_,
-      base::Bind(&ThumbnailLoader::DidReceiveBitmap,
-                 weak_factory_.GetWeakPtr()),
-      page_size,
-      pixel_size);
-}
-
-}  // namespace tabpose
-
-@implementation ThumbnailLayer
-
-- (id)initWithWebContents:(content::WebContents*)contents
-                 fullSize:(NSSize)fullSize {
-  CHECK(contents);
-  if ((self = [super init])) {
-    contents_ = contents;
-    fullSize_ = fullSize;
-  }
-  return self;
-}
-
-- (void)setWebContents:(content::WebContents*)contents {
-  contents_ = contents;
-}
-
-- (void)setThumbnail:(const SkBitmap&)bitmap {
-  // SkCreateCGImageRef() holds on to |bitmaps|'s memory, so this doesn't
-  // create a copy. The renderer always draws data in the system colorspace.
-  thumbnail_.reset(SkCreateCGImageRefWithColorspace(
-      bitmap, base::mac::GetSystemColorSpace()));
-  loader_ = NULL;
-  [self setNeedsDisplay];
-}
-
-- (int)topOffset {
-  int topOffset = 0;
-
-  // Medium term, we want to show thumbs of the actual info bar views, which
-  // means I need to create InfoBarControllers here.
-  NSWindow* window = [contents_->GetView()->GetNativeView() window];
-  NSWindowController* windowController = [window windowController];
-  if ([windowController isKindOfClass:[BrowserWindowController class]]) {
-    BrowserWindowController* bwc =
-        static_cast<BrowserWindowController*>(windowController);
-    InfoBarContainerController* infoBarContainer =
-        [bwc infoBarContainerController];
-    // TODO(thakis|rsesek): This is not correct for background tabs with
-    // infobars as the aspect ratio will be wrong. Fix that.
-    topOffset += NSHeight([[infoBarContainer view] frame]) -
-        [infoBarContainer overlappingTipHeight];
-  }
-
-  BookmarkTabHelper* bookmark_tab_helper =
-      BookmarkTabHelper::FromWebContents(contents_);
-  Profile* profile =
-      Profile::FromBrowserContext(contents_->GetBrowserContext());
-  bool always_show_bookmark_bar =
-      profile->GetPrefs()->GetBoolean(prefs::kShowBookmarkBar);
-  bool has_detached_bookmark_bar =
-      bookmark_tab_helper->ShouldShowBookmarkBar() &&
-      !always_show_bookmark_bar;
-  if (has_detached_bookmark_bar)
-    topOffset += chrome::kNTPBookmarkBarHeight;
-
-  return topOffset;
-}
-
-- (int)bottomOffset {
-  int bottomOffset = 0;
-  DevToolsWindow* devToolsWindow =
-      DevToolsWindow::GetDockedInstanceForInspectedTab(contents_);
-  content::WebContents* devToolsContents =
-      devToolsWindow ? devToolsWindow->web_contents() : NULL;
-  if (devToolsContents && devToolsContents->GetRenderViewHost() &&
-      devToolsContents->GetRenderViewHost()->GetView()) {
-    // The devtool's size might not be up-to-date, but since its height doesn't
-    // change on window resize, and since most users don't use devtools, this is
-    // good enough.
-    bottomOffset += devToolsContents->GetRenderViewHost()->GetView()->
-        GetViewBounds().height();
-    bottomOffset += 1;  // :-( Divider line between web contents and devtools.
-  }
-  return bottomOffset;
-}
-
-- (void)drawInContext:(CGContextRef)context {
-  RenderWidgetHost* rwh = contents_->GetRenderViewHost();
-  // NULL if renderer crashed.
-  content::RenderWidgetHostView* rwhv = rwh ? rwh->GetView() : NULL;
-  if (!rwhv) {
-    // TODO(thakis): Maybe draw a sad tab layer?
-    [super drawInContext:context];
-    return;
-  }
-
-  // The size of the WebContents's RenderWidgetHost might not fit to the
-  // current browser window at all, for example if the window was resized while
-  // this WebContents object was not an active tab.
-  // Compute the required size ourselves. Leave room for eventual infobars and
-  // a detached bookmarks bar on the top, and for the devtools on the bottom.
-  // Download shelf is not included in the |fullSize| rect, so no need to
-  // correct for it here.
-  // TODO(thakis): This is not resolution-independent.
-  int topOffset = [self topOffset];
-  int bottomOffset = [self bottomOffset];
-  gfx::Size desiredThumbSize(fullSize_.width,
-                             fullSize_.height - topOffset - bottomOffset);
-
-  // We need to ask the renderer for a thumbnail if
-  // a) there's no backing store or
-  // b) the backing store's size doesn't match our required size and
-  // c) we didn't already send a thumbnail request to the renderer.
-  bool draw_backing_store = rwh->GetBackingStoreSize() == desiredThumbSize;
-
-  // Next weirdness: The destination rect. If the layer is |fullSize_| big, the
-  // destination rect is (0, bottomOffset), (fullSize_.width, topOffset). But we
-  // might be amidst an animation, so interpolate that rect.
-  CGRect destRect = [self bounds];
-  CGFloat scale = destRect.size.width / fullSize_.width;
-  destRect.origin.y += bottomOffset * scale;
-  destRect.size.height -= (bottomOffset + topOffset) * scale;
-
-  // TODO(thakis): Draw infobars, detached bookmark bar as well.
-
-  // If we haven't already, sent a thumbnail request to the renderer.
-  if (!draw_backing_store && !didSendLoad_) {
-    // Either the tab was never visible, or its backing store got evicted, or
-    // the size of the backing store is wrong.
-
-    // We only need a thumbnail the size of the zoomed-out layer for all
-    // layers except the one the user clicks on. But since we can't know which
-    // layer that is, request full-resolution layers for all tabs. This is
-    // simple and seems to work in practice.
-    loader_ = new tabpose::ThumbnailLoader(desiredThumbSize, rwh, self);
-    loader_->LoadThumbnail();
-    didSendLoad_ = YES;
-
-    // Fill with bg color.
-    [super drawInContext:context];
-  }
-
-  if (draw_backing_store) {
-    // Backing store 'cache' hit!
-    // TODO(thakis): Add a sublayer for each accelerated surface in the rwhv.
-    // Until then, accelerated layers (CoreAnimation NPAPI plugins, compositor)
-    // won't show up in tabpose.
-    rwh->CopyFromBackingStoreToCGContext(destRect, context);
-  } else if (thumbnail_) {
-    // No cache hit, but the renderer returned a thumbnail to us.
-    gfx::ScopedCGContextSaveGState save_gstate(context);
-    CGContextSetInterpolationQuality(context, kCGInterpolationHigh);
-    CGContextDrawImage(context, destRect, thumbnail_.get());
-  }
-}
-
-@end
-
-// Given the number |n| of tiles with a desired aspect ratio of |a| and a
-// desired distance |dx|, |dy| between tiles, returns how many tiles fit
-// vertically into a rectangle with the dimensions |w_c|, |h_c|. This returns
-// an exact solution, which is usually a fractional number.
-static float FitNRectsWithAspectIntoBoundingSizeWithConstantPadding(
-    int n, double a, int w_c, int h_c, int dx, int dy) {
-  // We want to have the small rects have the same aspect ratio a as a full
-  // tab. Let w, h be the size of a small rect, and w_c, h_c the size of the
-  // container. dx, dy are the distances between small rects in x, y direction.
-
-  // Geometry yields:
-  // w_c = nx * (w + dx) - dx <=> w = (w_c + d_x) / nx - d_x
-  // h_c = ny * (h + dy) - dy <=> h = (h_c + d_y) / ny - d_t
-  // Plugging this into
-  // a := tab_width / tab_height = w / h
-  // yields
-  // a = ((w_c - (nx - 1)*d_x)*ny) / (nx*(h_c - (ny - 1)*d_y))
-  // Plugging in nx = n/ny and pen and paper (or wolfram alpha:
-  // http://www.wolframalpha.com/input/?i=(-sqrt((d+n-a+f+n)^2-4+(a+f%2Ba+h)+(-d+n-n+w))%2Ba+f+n-d+n)/(2+a+(f%2Bh)) , (solution for nx)
-  // http://www.wolframalpha.com/input/?i=+(-sqrt((a+f+n-d+n)^2-4+(d%2Bw)+(-a+f+n-a+h+n))-a+f+n%2Bd+n)/(2+(d%2Bw)) , (solution for ny)
-  // ) gives us nx and ny (but the wrong root -- s/-sqrt(FOO)/sqrt(FOO)/.
-
-  // This function returns ny.
-  return (sqrt(pow(n * (a * dy - dx), 2) +
-               4 * n * a * (dx + w_c) * (dy + h_c)) -
-          n * (a * dy - dx))
-      /
-         (2 * (dx + w_c));
-}
-
-namespace tabpose {
-
-CGFloat ScaleWithOrigin(CGFloat x, CGFloat origin, CGFloat scale) {
-  return (x - origin) * scale + origin;
-}
-
-NSRect ScaleRectWithOrigin(NSRect r, NSPoint p, CGFloat scale) {
-  return NSMakeRect(ScaleWithOrigin(NSMinX(r), p.x, scale),
-                    ScaleWithOrigin(NSMinY(r), p.y, scale),
-                    NSWidth(r) * scale,
-                    NSHeight(r) * scale);
-}
-
-// A tile is what is shown for a single tab in tabpose mode. It consists of a
-// title, favicon, thumbnail image, and pre- and postanimation rects.
-class Tile {
- public:
-  Tile() {}
-
-  // Returns the rectangle this thumbnail is at at the beginning of the zoom-in
-  // animation. |tile| is the rectangle that's covering the whole tab area when
-  // the animation starts.
-  NSRect GetStartRectRelativeTo(const Tile& tile) const;
-  NSRect thumb_rect() const { return thumb_rect_; }
-
-  NSRect GetFaviconStartRectRelativeTo(const Tile& tile) const;
-  NSRect favicon_rect() const { return NSIntegralRect(favicon_rect_); }
-  NSImage* favicon() const;
-
-  // This changes |title_rect| and |favicon_rect| such that the favicon is on
-  // the font's baseline and that the minimum distance between thumb rect and
-  // favicon and title rects doesn't change.
-  // The view code
-  // 1. queries desired font size by calling |title_font_size()|
-  // 2. loads that font
-  // 3. calls |set_font_metrics()| which updates the title rect
-  // 4. receives the title rect and puts the title on it with the font from 2.
-  void set_font_metrics(CGFloat ascender, CGFloat descender);
-  CGFloat title_font_size() const { return title_font_size_; }
-
-  NSRect GetTitleStartRectRelativeTo(const Tile& tile) const;
-  NSRect title_rect() const { return NSIntegralRect(title_rect_); }
-
-  // Returns an unelided title. The view logic is responsible for eliding.
-  const base::string16& title() const {
-    return contents_->GetTitle();
-  }
-
-  content::WebContents* web_contents() const { return contents_; }
-  void set_tab_contents(content::WebContents* new_contents) {
-    contents_ = new_contents;
-  }
-
- private:
-  friend class TileSet;
-
-  // The thumb rect includes infobars, detached thumbnail bar, web contents,
-  // and devtools.
-  NSRect thumb_rect_;
-  NSRect start_thumb_rect_;
-
-  NSRect favicon_rect_;
-
-  CGFloat title_font_size_;
-  NSRect title_rect_;
-
-  content::WebContents* contents_;  // weak
-
-  DISALLOW_COPY_AND_ASSIGN(Tile);
-};
-
-NSRect Tile::GetStartRectRelativeTo(const Tile& tile) const {
-  NSRect rect = start_thumb_rect_;
-  rect.origin.x -= tile.start_thumb_rect_.origin.x;
-  rect.origin.y -= tile.start_thumb_rect_.origin.y;
-  return rect;
-}
-
-NSRect Tile::GetFaviconStartRectRelativeTo(const Tile& tile) const {
-  NSRect thumb_start = GetStartRectRelativeTo(tile);
-  CGFloat scale_to_start = NSWidth(thumb_start) / NSWidth(thumb_rect_);
-  NSRect rect =
-      ScaleRectWithOrigin(favicon_rect_, thumb_rect_.origin, scale_to_start);
-  rect.origin.x += NSMinX(thumb_start) - NSMinX(thumb_rect_);
-  rect.origin.y += NSMinY(thumb_start) - NSMinY(thumb_rect_);
-  return rect;
-}
-
-NSImage* Tile::favicon() const {
-  extensions::TabHelper* extensions_tab_helper =
-      extensions::TabHelper::FromWebContents(contents_);
-  if (extensions_tab_helper->is_app()) {
-    SkBitmap* bitmap = extensions_tab_helper->GetExtensionAppIcon();
-    if (bitmap)
-      return gfx::SkBitmapToNSImage(*bitmap);
-  }
-  return mac::FaviconForWebContents(contents_);
-}
-
-NSRect Tile::GetTitleStartRectRelativeTo(const Tile& tile) const {
-  NSRect thumb_start = GetStartRectRelativeTo(tile);
-  CGFloat scale_to_start = NSWidth(thumb_start) / NSWidth(thumb_rect_);
-  NSRect rect =
-      ScaleRectWithOrigin(title_rect_, thumb_rect_.origin, scale_to_start);
-  rect.origin.x += NSMinX(thumb_start) - NSMinX(thumb_rect_);
-  rect.origin.y += NSMinY(thumb_start) - NSMinY(thumb_rect_);
-  return rect;
-}
-
-// Changes |title_rect| and |favicon_rect| such that the favicon's and the
-// title's vertical center is aligned and that the minimum distance between
-// the thumb rect and favicon and title rects doesn't change.
-void Tile::set_font_metrics(CGFloat ascender, CGFloat descender) {
-  // Make the title height big enough to fit the font, and adopt the title
-  // position to keep its distance from the thumb rect.
-  title_rect_.origin.y -= ascender + descender - NSHeight(title_rect_);
-  title_rect_.size.height = ascender + descender;
-
-  // Align vertical center. Both rects are currently aligned on their top edge.
-  CGFloat delta_y = NSMidY(title_rect_) - NSMidY(favicon_rect_);
-  if (delta_y > 0) {
-    // Title is higher: Move favicon down to align the centers.
-    favicon_rect_.origin.y += delta_y;
-  } else {
-    // Favicon is higher: Move title down to align the centers.
-    title_rect_.origin.y -= delta_y;
-  }
-}
-
-// A tileset is responsible for owning and laying out all |Tile|s shown in a
-// tabpose window.
-class TileSet {
- public:
-  TileSet() {}
-
-  // Fills in |tiles_|.
-  void Build(TabStripModel* source_model);
-
-  // Computes coordinates for |tiles_|.
-  void Layout(NSRect containing_rect);
-
-  int selected_index() const { return selected_index_; }
-  void set_selected_index(int index);
-
-  const Tile& selected_tile() const { return *tiles_[selected_index()]; }
-  Tile& tile_at(int index) { return *tiles_[index]; }
-  const Tile& tile_at(int index) const { return *tiles_[index]; }
-
-  // These return which index needs to be selected when the user presses
-  // up, down, left, or right respectively.
-  int up_index() const;
-  int down_index() const;
-  int left_index() const;
-  int right_index() const;
-
-  // These return which index needs to be selected on tab / shift-tab.
-  int next_index() const;
-  int previous_index() const;
-
-  // Inserts a new Tile object containing |contents| at |index|. Does no
-  // relayout.
-  void InsertTileAt(int index, content::WebContents* contents);
-
-  // Removes the Tile object at |index|. Does no relayout.
-  void RemoveTileAt(int index);
-
-  // Moves the Tile object at |from_index| to |to_index|. Since this doesn't
-  // change the number of tiles, relayout can be done just by swapping the
-  // tile rectangles in the index interval [from_index, to_index], so this does
-  // layout.
-  void MoveTileFromTo(int from_index, int to_index);
-
- private:
-  int count_x() const {
-    return ceilf(tiles_.size() / static_cast<float>(count_y_));
-  }
-  int count_y() const {
-    return count_y_;
-  }
-  int last_row_count_x() const {
-    return tiles_.size() - count_x() * (count_y() - 1);
-  }
-  int tiles_in_row(int row) const {
-    return row != count_y() - 1 ? count_x() : last_row_count_x();
-  }
-  void index_to_tile_xy(int index, int* tile_x, int* tile_y) const {
-    *tile_x = index % count_x();
-    *tile_y = index / count_x();
-  }
-  int tile_xy_to_index(int tile_x, int tile_y) const {
-    return tile_y * count_x() + tile_x;
-  }
-
-  ScopedVector<Tile> tiles_;
-  int selected_index_;
-  int count_y_;
-
-  DISALLOW_COPY_AND_ASSIGN(TileSet);
-};
-
-void TileSet::Build(TabStripModel* source_model) {
-  selected_index_ =  source_model->active_index();
-  tiles_.resize(source_model->count());
-  for (size_t i = 0; i < tiles_.size(); ++i) {
-    tiles_[i] = new Tile;
-    tiles_[i]->contents_ = source_model->GetWebContentsAt(i);
-  }
-}
-
-void TileSet::Layout(NSRect containing_rect) {
-  int tile_count = tiles_.size();
-  if (tile_count == 0)  // Happens e.g. during test shutdown.
-    return;
-
-  // Room around the tiles insde of |containing_rect|.
-  const int kSmallPaddingTop = 30;
-  const int kSmallPaddingLeft = 30;
-  const int kSmallPaddingRight = 30;
-  const int kSmallPaddingBottom = 30;
-
-  // Favicon / title area.
-  const int kThumbTitlePaddingY = 6;
-  const int kFaviconSize = 16;
-  const int kTitleHeight = 14;  // Font size.
-  const int kTitleExtraHeight = kThumbTitlePaddingY + kTitleHeight;
-  const int kFaviconExtraHeight = kThumbTitlePaddingY + kFaviconSize;
-  const int kFaviconTitleDistanceX = 6;
-  const int kFooterExtraHeight =
-      std::max(kFaviconExtraHeight, kTitleExtraHeight);
-
-  // Room between the tiles.
-  const int kSmallPaddingX = 15;
-  const int kSmallPaddingY = kFooterExtraHeight;
-
-  // Aspect ratio of the containing rect.
-  CGFloat aspect = NSWidth(containing_rect) / NSHeight(containing_rect);
-
-  // Room left in container after the outer padding is removed.
-  double container_width =
-      NSWidth(containing_rect) - kSmallPaddingLeft - kSmallPaddingRight;
-  double container_height =
-      NSHeight(containing_rect) - kSmallPaddingTop - kSmallPaddingBottom;
-
-  // The tricky part is figuring out the size of a tab thumbnail, or since the
-  // size of the containing rect is known, the number of tiles in x and y
-  // direction.
-  // Given are the size of the containing rect, and the number of thumbnails
-  // that need to fit into that rect. The aspect ratio of the thumbnails needs
-  // to be the same as that of |containing_rect|, else they will look distorted.
-  // The thumbnails need to be distributed such that
-  // |count_x * count_y >= tile_count|, and such that wasted space is minimized.
-  //  See the comments in
-  // |FitNRectsWithAspectIntoBoundingSizeWithConstantPadding()| for a more
-  // detailed discussion.
-  // TODO(thakis): It might be good enough to choose |count_x| and |count_y|
-  //   such that count_x / count_y is roughly equal to |aspect|?
-  double fny = FitNRectsWithAspectIntoBoundingSizeWithConstantPadding(
-      tile_count, aspect,
-      container_width, container_height - kFooterExtraHeight,
-      kSmallPaddingX, kSmallPaddingY + kFooterExtraHeight);
-  count_y_ = roundf(fny);
-
-  // Now that |count_x()| and |count_y_| are known, it's straightforward to
-  // compute thumbnail width/height. See comment in
-  // |FitNRectsWithAspectIntoBoundingSizeWithConstantPadding| for the derivation
-  // of these two formulas.
-  int small_width =
-      floor((container_width + kSmallPaddingX) / static_cast<float>(count_x()) -
-            kSmallPaddingX);
-  int small_height =
-      floor((container_height + kSmallPaddingY) / static_cast<float>(count_y_) -
-            (kSmallPaddingY + kFooterExtraHeight));
-
-  // |small_width / small_height| has only roughly an aspect ratio of |aspect|.
-  // Shrink the thumbnail rect to make the aspect ratio fit exactly, and add
-  // the extra space won by shrinking to the outer padding.
-  int smallExtraPaddingLeft = 0;
-  int smallExtraPaddingTop = 0;
-  if (aspect > small_width/static_cast<float>(small_height)) {
-    small_height = small_width / aspect;
-    CGFloat all_tiles_height =
-        (small_height + kSmallPaddingY + kFooterExtraHeight) * count_y() -
-        (kSmallPaddingY + kFooterExtraHeight);
-    smallExtraPaddingTop = (container_height - all_tiles_height)/2;
-  } else {
-    small_width = small_height * aspect;
-    CGFloat all_tiles_width =
-        (small_width + kSmallPaddingX) * count_x() - kSmallPaddingX;
-    smallExtraPaddingLeft = (container_width - all_tiles_width)/2;
-  }
-
-  // Compute inter-tile padding in the zoomed-out view.
-  CGFloat scale_small_to_big =
-      NSWidth(containing_rect) / static_cast<float>(small_width);
-  CGFloat big_padding_x = kSmallPaddingX * scale_small_to_big;
-  CGFloat big_padding_y =
-      (kSmallPaddingY + kFooterExtraHeight) * scale_small_to_big;
-
-  // Now all dimensions are known. Lay out all tiles on a regular grid:
-  // X X X X
-  // X X X X
-  // X X
-  for (int row = 0, i = 0; i < tile_count; ++row) {
-    for (int col = 0; col < count_x() && i < tile_count; ++col, ++i) {
-      // Compute the smalled, zoomed-out thumbnail rect.
-      tiles_[i]->thumb_rect_.size = NSMakeSize(small_width, small_height);
-
-      int small_x = col * (small_width + kSmallPaddingX) +
-                    kSmallPaddingLeft + smallExtraPaddingLeft;
-      int small_y = row * (small_height + kSmallPaddingY + kFooterExtraHeight) +
-                    kSmallPaddingTop + smallExtraPaddingTop;
-
-      tiles_[i]->thumb_rect_.origin = NSMakePoint(
-          small_x, NSHeight(containing_rect) - small_y - small_height);
-
-      tiles_[i]->favicon_rect_.size = NSMakeSize(kFaviconSize, kFaviconSize);
-      tiles_[i]->favicon_rect_.origin = NSMakePoint(
-          small_x,
-          NSHeight(containing_rect) -
-              (small_y + small_height + kFaviconExtraHeight));
-
-      // Align lower left corner of title rect with lower left corner of favicon
-      // for now. The final position is computed later by
-      // |Tile::set_font_metrics()|.
-      tiles_[i]->title_font_size_ = kTitleHeight;
-      tiles_[i]->title_rect_.origin = NSMakePoint(
-          NSMaxX(tiles_[i]->favicon_rect()) + kFaviconTitleDistanceX,
-          NSMinY(tiles_[i]->favicon_rect()));
-      tiles_[i]->title_rect_.size = NSMakeSize(
-          small_width -
-              NSWidth(tiles_[i]->favicon_rect()) - kFaviconTitleDistanceX,
-          kTitleHeight);
-
-      // Compute the big, pre-zoom thumbnail rect.
-      tiles_[i]->start_thumb_rect_.size = containing_rect.size;
-
-      int big_x = col * (NSWidth(containing_rect) + big_padding_x);
-      int big_y = row * (NSHeight(containing_rect) + big_padding_y);
-      tiles_[i]->start_thumb_rect_.origin = NSMakePoint(big_x, -big_y);
-    }
-  }
-}
-
-void TileSet::set_selected_index(int index) {
-  CHECK_GE(index, 0);
-  CHECK_LT(index, static_cast<int>(tiles_.size()));
-  selected_index_ = index;
-}
-
-// Given a |value| in [0, from_scale), map it into [0, to_scale) such that:
-// * [0, from_scale) ends up in the middle of [0, to_scale) if the latter is
-//   a bigger range
-// * The middle of [0, from_scale) is mapped to [0, to_scale), and the parts
-//   of the former that don't fit are mapped to 0 and to_scale - respectively
-//   if the former is a bigger range.
-static int rescale(int value, int from_scale, int to_scale) {
-  int left = (to_scale - from_scale) / 2;
-  int result = value + left;
-  if (result < 0)
-    return 0;
-  if (result >= to_scale)
-    return to_scale - 1;
-  return result;
-}
-
-int TileSet::up_index() const {
-  int tile_x, tile_y;
-  index_to_tile_xy(selected_index(), &tile_x, &tile_y);
-  tile_y -= 1;
-  if (tile_y == count_y() - 2) {
-    // Transition from last row to second-to-last row.
-    tile_x = rescale(tile_x, last_row_count_x(), count_x());
-  } else if (tile_y < 0) {
-    // Transition from first row to last row.
-    tile_x = rescale(tile_x, count_x(), last_row_count_x());
-    tile_y = count_y() - 1;
-  }
-  return tile_xy_to_index(tile_x, tile_y);
-}
-
-int TileSet::down_index() const {
-  int tile_x, tile_y;
-  index_to_tile_xy(selected_index(), &tile_x, &tile_y);
-  tile_y += 1;
-  if (tile_y == count_y() - 1) {
-    // Transition from second-to-last row to last row.
-    tile_x = rescale(tile_x, count_x(), last_row_count_x());
-  } else if (tile_y >= count_y()) {
-    // Transition from last row to first row.
-    tile_x = rescale(tile_x, last_row_count_x(), count_x());
-    tile_y = 0;
-  }
-  return tile_xy_to_index(tile_x, tile_y);
-}
-
-int TileSet::left_index() const {
-  int tile_x, tile_y;
-  index_to_tile_xy(selected_index(), &tile_x, &tile_y);
-  tile_x -= 1;
-  if (tile_x < 0)
-    tile_x = tiles_in_row(tile_y) - 1;
-  return tile_xy_to_index(tile_x, tile_y);
-}
-
-int TileSet::right_index() const {
-  int tile_x, tile_y;
-  index_to_tile_xy(selected_index(), &tile_x, &tile_y);
-  tile_x += 1;
-  if (tile_x >= tiles_in_row(tile_y))
-    tile_x = 0;
-  return tile_xy_to_index(tile_x, tile_y);
-}
-
-int TileSet::next_index() const {
-  int new_index = selected_index() + 1;
-  if (new_index >= static_cast<int>(tiles_.size()))
-    new_index = 0;
-  return new_index;
-}
-
-int TileSet::previous_index() const {
-  int new_index = selected_index() - 1;
-  if (new_index < 0)
-    new_index = tiles_.size() - 1;
-  return new_index;
-}
-
-void TileSet::InsertTileAt(int index, content::WebContents* contents) {
-  tiles_.insert(tiles_.begin() + index, new Tile);
-  tiles_[index]->contents_ = contents;
-}
-
-void TileSet::RemoveTileAt(int index) {
-  tiles_.erase(tiles_.begin() + index);
-}
-
-// Moves the Tile object at |from_index| to |to_index|. Also updates rectangles
-// so that the tiles stay in a left-to-right, top-to-bottom layout when walked
-// in sequential order.
-void TileSet::MoveTileFromTo(int from_index, int to_index) {
-  NSRect thumb = tiles_[from_index]->thumb_rect_;
-  NSRect start_thumb = tiles_[from_index]->start_thumb_rect_;
-  NSRect favicon = tiles_[from_index]->favicon_rect_;
-  NSRect title = tiles_[from_index]->title_rect_;
-
-  scoped_ptr<Tile> tile(tiles_[from_index]);
-  tiles_.weak_erase(tiles_.begin() + from_index);
-  tiles_.insert(tiles_.begin() + to_index, tile.release());
-
-  int step = from_index < to_index ? -1 : 1;
-  for (int i = to_index; (i - from_index) * step < 0; i += step) {
-    tiles_[i]->thumb_rect_ = tiles_[i + step]->thumb_rect_;
-    tiles_[i]->start_thumb_rect_ = tiles_[i + step]->start_thumb_rect_;
-    tiles_[i]->favicon_rect_ = tiles_[i + step]->favicon_rect_;
-    tiles_[i]->title_rect_ = tiles_[i + step]->title_rect_;
-  }
-  tiles_[from_index]->thumb_rect_ = thumb;
-  tiles_[from_index]->start_thumb_rect_ = start_thumb;
-  tiles_[from_index]->favicon_rect_ = favicon;
-  tiles_[from_index]->title_rect_ = title;
-}
-
-}  // namespace tabpose
-
-void AnimateScaledCALayerFrameFromTo(
-    CALayer* layer,
-    const NSRect& from, CGFloat from_scale,
-    const NSRect& to, CGFloat to_scale,
-    NSTimeInterval duration, id boundsAnimationDelegate) {
-  // http://developer.apple.com/mac/library/qa/qa2008/qa1620.html
-  CABasicAnimation* animation;
-
-  animation = [CABasicAnimation animationWithKeyPath:@"bounds"];
-  animation.fromValue = [NSValue valueWithRect:from];
-  animation.toValue = [NSValue valueWithRect:to];
-  animation.duration = duration;
-  animation.timingFunction =
-      [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
-  animation.delegate = boundsAnimationDelegate;
-
-  // Update the layer's bounds so the layer doesn't snap back when the animation
-  // completes.
-  layer.bounds = NSRectToCGRect(to);
-
-  // Add the animation, overriding the implicit animation.
-  [layer addAnimation:animation forKey:@"bounds"];
-
-  // Prepare the animation from the current position to the new position.
-  NSPoint opoint = from.origin;
-  NSPoint point = to.origin;
-
-  // Adapt to anchorPoint.
-  opoint.x += NSWidth(from) * from_scale * layer.anchorPoint.x;
-  opoint.y += NSHeight(from) * from_scale * layer.anchorPoint.y;
-  point.x += NSWidth(to) * to_scale * layer.anchorPoint.x;
-  point.y += NSHeight(to) * to_scale * layer.anchorPoint.y;
-
-  animation = [CABasicAnimation animationWithKeyPath:@"position"];
-  animation.fromValue = [NSValue valueWithPoint:opoint];
-  animation.toValue = [NSValue valueWithPoint:point];
-  animation.duration = duration;
-  animation.timingFunction =
-      [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
-
-  // Update the layer's position so that the layer doesn't snap back when the
-  // animation completes.
-  layer.position = NSPointToCGPoint(point);
-
-  // Add the animation, overriding the implicit animation.
-  [layer addAnimation:animation forKey:@"position"];
-}
-
-void AnimateCALayerFrameFromTo(
-    CALayer* layer, const NSRect& from, const NSRect& to,
-    NSTimeInterval duration, id boundsAnimationDelegate) {
-  AnimateScaledCALayerFrameFromTo(
-      layer, from, 1.0, to, 1.0, duration, boundsAnimationDelegate);
-}
-
-void AnimateCALayerOpacityFromTo(
-    CALayer* layer, double from, double to, NSTimeInterval duration) {
-  CABasicAnimation* animation;
-  animation = [CABasicAnimation animationWithKeyPath:@"opacity"];
-  animation.fromValue = [NSNumber numberWithFloat:from];
-  animation.toValue = [NSNumber numberWithFloat:to];
-  animation.duration = duration;
-
-  layer.opacity = to;
-  // Add the animation, overriding the implicit animation.
-  [layer addAnimation:animation forKey:@"opacity"];
-}
-
-@interface TabposeWindow (Private)
-- (id)initForWindow:(NSWindow*)parent
-               rect:(NSRect)rect
-              slomo:(BOOL)slomo
-      tabStripModel:(TabStripModel*)tabStripModel;
-
-// Creates and initializes the CALayer in the background and all the CALayers
-// for the thumbnails, favicons, and titles.
-- (void)setUpLayersInSlomo:(BOOL)slomo;
-
-// Tells the browser to make the tab corresponding to currently selected
-// thumbnail the current tab and starts the tabpose exit animmation.
-- (void)fadeAwayInSlomo:(BOOL)slomo;
-
-// Returns the CALayer for the close button belonging to the thumbnail at
-// index |index|.
-- (CALayer*)closebuttonLayerAtIndex:(NSUInteger)index;
-
-// Updates the visibility of all closebutton layers.
-- (void)updateClosebuttonLayersVisibility;
-@end
-
-@implementation TabposeWindow
-
-+ (id)openTabposeFor:(NSWindow*)parent
-                rect:(NSRect)rect
-               slomo:(BOOL)slomo
-       tabStripModel:(TabStripModel*)tabStripModel {
-  // Releases itself when closed.
-  return [[TabposeWindow alloc]
-      initForWindow:parent rect:rect slomo:slomo tabStripModel:tabStripModel];
-}
-
-- (id)initForWindow:(NSWindow*)parent
-               rect:(NSRect)rect
-              slomo:(BOOL)slomo
-      tabStripModel:(TabStripModel*)tabStripModel {
-  NSRect frame = [parent frame];
-  if ((self = [super initWithContentRect:frame
-                               styleMask:NSBorderlessWindowMask
-                                 backing:NSBackingStoreBuffered
-                                   defer:NO])) {
-    containingRect_ = rect;
-    tabStripModel_ = tabStripModel;
-    state_ = tabpose::kFadingIn;
-    tileSet_.reset(new tabpose::TileSet);
-    tabStripModelObserverBridge_.reset(
-        new TabStripModelObserverBridge(tabStripModel_, self));
-    closeIcon_.reset([ResourceBundle::GetSharedInstance().GetNativeImageNamed(
-            IDR_TABPOSE_CLOSE).ToNSImage() retain]);
-    [self setReleasedWhenClosed:YES];
-    [self setOpaque:NO];
-    [self setBackgroundColor:[NSColor clearColor]];
-    [self setUpLayersInSlomo:slomo];
-    [self setAcceptsMouseMovedEvents:YES];
-    [parent addChildWindow:self ordered:NSWindowAbove];
-    [self makeKeyAndOrderFront:self];
-  }
-  return self;
-}
-
-- (CALayer*)selectedLayer {
-  return [allThumbnailLayers_ objectAtIndex:tileSet_->selected_index()];
-}
-
-- (void)selectTileAtIndexWithoutAnimation:(int)newIndex {
-  ScopedCAActionDisabler disabler;
-  const tabpose::Tile& tile = tileSet_->tile_at(newIndex);
-  selectionHighlight_.frame =
-      NSRectToCGRect(NSInsetRect(tile.thumb_rect(),
-                     -kSelectionInset, -kSelectionInset));
-  tileSet_->set_selected_index(newIndex);
-
-  [self updateClosebuttonLayersVisibility];
-}
-
-- (void)addLayersForTile:(tabpose::Tile&)tile
-                showZoom:(BOOL)showZoom
-                   slomo:(BOOL)slomo
-       animationDelegate:(id)animationDelegate {
-  base::scoped_nsobject<CALayer> layer(
-      [[ThumbnailLayer alloc] initWithWebContents:tile.web_contents()
-                                         fullSize:tile.GetStartRectRelativeTo(
-                                             tileSet_->selected_tile()).size]);
-  [layer setNeedsDisplay];
-
-  NSTimeInterval interval =
-      kDefaultAnimationDuration * (slomo ? kSlomoFactor : 1);
-
-  // Background color as placeholder for now.
-  layer.get().backgroundColor = CGColorGetConstantColor(kCGColorWhite);
-  if (showZoom) {
-    AnimateCALayerFrameFromTo(
-        layer,
-        tile.GetStartRectRelativeTo(tileSet_->selected_tile()),
-        tile.thumb_rect(),
-        interval,
-        animationDelegate);
-  } else {
-    layer.get().frame = NSRectToCGRect(tile.thumb_rect());
-  }
-
-  layer.get().shadowRadius = 10;
-  layer.get().shadowOffset = CGSizeMake(0, -10);
-  if (state_ == tabpose::kFadedIn)
-    layer.get().shadowOpacity = 0.5;
-
-  // Add a close button to the thumb layer.
-  CALayer* closeLayer = [CALayer layer];
-  closeLayer.contents = closeIcon_.get();
-  CGRect closeBounds = {};
-  closeBounds.size = NSSizeToCGSize([closeIcon_ size]);
-  closeLayer.bounds = closeBounds;
-  closeLayer.hidden = YES;
-
-  [closeLayer addConstraint:
-      [CAConstraint constraintWithAttribute:kCAConstraintMidX
-                                 relativeTo:@"superlayer"
-                                  attribute:kCAConstraintMinX]];
-  [closeLayer addConstraint:
-      [CAConstraint constraintWithAttribute:kCAConstraintMidY
-                                 relativeTo:@"superlayer"
-                                  attribute:kCAConstraintMaxY]];
-
-  layer.get().layoutManager = [CAConstraintLayoutManager layoutManager];
-  [layer.get() addSublayer:closeLayer];
-
-  [bgLayer_ addSublayer:layer];
-  [allThumbnailLayers_ addObject:layer];
-
-  // Favicon and title.
-  NSFont* font = [NSFont systemFontOfSize:tile.title_font_size()];
-  tile.set_font_metrics([font ascender], -[font descender]);
-
-  CALayer* faviconLayer = [CALayer layer];
-  if (showZoom) {
-    AnimateCALayerFrameFromTo(
-        faviconLayer,
-        tile.GetFaviconStartRectRelativeTo(tileSet_->selected_tile()),
-        tile.favicon_rect(),
-        interval,
-        nil);
-    AnimateCALayerOpacityFromTo(faviconLayer, 0.0, 1.0, interval);
-  } else {
-    faviconLayer.frame = NSRectToCGRect(tile.favicon_rect());
-  }
-  faviconLayer.contents = tile.favicon();
-  faviconLayer.zPosition = 1;  // On top of the thumb shadow.
-  [bgLayer_ addSublayer:faviconLayer];
-  [allFaviconLayers_ addObject:faviconLayer];
-
-  // CATextLayers can't animate their fontSize property, at least on 10.5.
-  // Animate transform.scale instead.
-
-  // The scaling should have its origin in the layer's upper left corner.
-  // This needs to be set before |AnimateCALayerFrameFromTo()| is called.
-  CATextLayer* titleLayer = [CATextLayer layer];
-  titleLayer.anchorPoint = CGPointMake(0, 1);
-  if (showZoom) {
-    NSRect fromRect =
-        tile.GetTitleStartRectRelativeTo(tileSet_->selected_tile());
-    NSRect toRect = tile.title_rect();
-    CGFloat scale = NSWidth(fromRect) / NSWidth(toRect);
-    fromRect.size = toRect.size;
-
-    // Add scale animation.
-    CABasicAnimation* scaleAnimation =
-        [CABasicAnimation animationWithKeyPath:@"transform.scale"];
-    scaleAnimation.fromValue = [NSNumber numberWithDouble:scale];
-    scaleAnimation.toValue = [NSNumber numberWithDouble:1.0];
-    scaleAnimation.duration = interval;
-    scaleAnimation.timingFunction =
-        [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
-    [titleLayer addAnimation:scaleAnimation forKey:@"transform.scale"];
-
-    // Add the position and opacity animations.
-    AnimateScaledCALayerFrameFromTo(
-        titleLayer, fromRect, scale, toRect, 1.0, interval, nil);
-    AnimateCALayerOpacityFromTo(faviconLayer, 0.0, 1.0, interval);
-  } else {
-    titleLayer.frame = NSRectToCGRect(tile.title_rect());
-  }
-  titleLayer.string = base::SysUTF16ToNSString(tile.title());
-  titleLayer.fontSize = [font pointSize];
-  titleLayer.truncationMode = kCATruncationEnd;
-  titleLayer.font = font;
-  titleLayer.zPosition = 1;  // On top of the thumb shadow.
-  [bgLayer_ addSublayer:titleLayer];
-  [allTitleLayers_ addObject:titleLayer];
-}
-
-- (void)setUpLayersInSlomo:(BOOL)slomo {
-  // Root layer -- covers whole window.
-  rootLayer_ = [CALayer layer];
-
-  // In a block so that the layers don't fade in.
-  {
-    ScopedCAActionDisabler disabler;
-    // Background layer -- the visible part of the window.
-    gray_.reset(CGColorCreateGenericGray(kCentralGray, 1.0));
-    bgLayer_ = [CALayer layer];
-    bgLayer_.backgroundColor = gray_;
-    bgLayer_.frame = NSRectToCGRect(containingRect_);
-    bgLayer_.masksToBounds = YES;
-    [rootLayer_ addSublayer:bgLayer_];
-
-    // Selection highlight layer.
-    darkBlue_.reset(CGColorCreateGenericRGB(0.25, 0.34, 0.86, 1.0));
-    selectionHighlight_ = [CALayer layer];
-    selectionHighlight_.backgroundColor = darkBlue_;
-    selectionHighlight_.cornerRadius = 5.0;
-    selectionHighlight_.zPosition = -1;  // Behind other layers.
-    selectionHighlight_.hidden = YES;
-    [bgLayer_ addSublayer:selectionHighlight_];
-
-    // Bottom gradient.
-    CALayer* gradientLayer = [[[GrayGradientLayer alloc]
-        initWithStartGray:kCentralGray endGray:kBottomGray] autorelease];
-    gradientLayer.frame = CGRectMake(
-        0,
-        0,
-        NSWidth(containingRect_),
-        kBottomGradientHeight);
-    [gradientLayer setNeedsDisplay];  // Draw once.
-    [bgLayer_ addSublayer:gradientLayer];
-  }
-  // Top gradient (fades in).
-  CGFloat toolbarHeight = NSHeight([self frame]) - NSHeight(containingRect_);
-  topGradient_ = [[[GrayGradientLayer alloc]
-      initWithStartGray:kTopGray endGray:kCentralGray] autorelease];
-  topGradient_.frame = CGRectMake(
-      0,
-      NSHeight([self frame]) - toolbarHeight,
-      NSWidth(containingRect_),
-      toolbarHeight);
-  [topGradient_ setNeedsDisplay];  // Draw once.
-  [rootLayer_ addSublayer:topGradient_];
-  NSTimeInterval interval =
-      kDefaultAnimationDuration * (slomo ? kSlomoFactor : 1);
-  AnimateCALayerOpacityFromTo(topGradient_, 0, 1, interval);
-
-  // Layers for the tab thumbnails.
-  tileSet_->Build(tabStripModel_);
-  tileSet_->Layout(containingRect_);
-  allThumbnailLayers_.reset(
-      [[NSMutableArray alloc] initWithCapacity:tabStripModel_->count()]);
-  allFaviconLayers_.reset(
-      [[NSMutableArray alloc] initWithCapacity:tabStripModel_->count()]);
-  allTitleLayers_.reset(
-      [[NSMutableArray alloc] initWithCapacity:tabStripModel_->count()]);
-
-  for (int i = 0; i < tabStripModel_->count(); ++i) {
-    // Add a delegate to one of the animations to get a notification once the
-    // animations are done.
-    [self  addLayersForTile:tileSet_->tile_at(i)
-                 showZoom:YES
-                    slomo:slomo
-        animationDelegate:i == tileSet_->selected_index() ? self : nil];
-    if (i == tileSet_->selected_index()) {
-      CALayer* layer = [allThumbnailLayers_ objectAtIndex:i];
-      CAAnimation* animation = [layer animationForKey:@"bounds"];
-      DCHECK(animation);
-      [animation setValue:kAnimationIdFadeIn forKey:kAnimationIdKey];
-    }
-  }
-  [self selectTileAtIndexWithoutAnimation:tileSet_->selected_index()];
-
-  // Needs to happen after all layers have been added to |rootLayer_|, else
-  // there's a one frame flash of grey at the beginning of the animation
-  // (|bgLayer_| showing through with none of its children visible yet).
-  [[self contentView] setLayer:rootLayer_];
-  [[self contentView] setWantsLayer:YES];
-}
-
-- (BOOL)canBecomeKeyWindow {
- return YES;
-}
-
-// Lets the traffic light buttons on the browser window keep their "active"
-// state while an info bubble is open. Only has an effect on 10.7.
-- (BOOL)_sharesParentKeyState {
-  return YES;
-}
-
-// Handle key events that should be executed repeatedly while the key is down.
-- (void)keyDown:(NSEvent*)event {
-  if (state_ == tabpose::kFadingOut)
-    return;
-  NSString* characters = [event characters];
-  if ([characters length] < 1)
-    return;
-
-  unichar character = [characters characterAtIndex:0];
-  int newIndex = -1;
-  switch (character) {
-    case NSUpArrowFunctionKey:
-      newIndex = tileSet_->up_index();
-      break;
-    case NSDownArrowFunctionKey:
-      newIndex = tileSet_->down_index();
-      break;
-    case NSLeftArrowFunctionKey:
-      newIndex = tileSet_->left_index();
-      break;
-    case NSRightArrowFunctionKey:
-      newIndex = tileSet_->right_index();
-      break;
-    case NSTabCharacter:
-      newIndex = tileSet_->next_index();
-      break;
-    case NSBackTabCharacter:
-      newIndex = tileSet_->previous_index();
-      break;
-  }
-  if (newIndex != -1)
-    [self selectTileAtIndexWithoutAnimation:newIndex];
-}
-
-// Handle keyboard events that should be executed once when the key is released.
-- (void)keyUp:(NSEvent*)event {
-  if (state_ == tabpose::kFadingOut)
-    return;
-  NSString* characters = [event characters];
-  if ([characters length] < 1)
-    return;
-
-  unichar character = [characters characterAtIndex:0];
-  switch (character) {
-    case NSEnterCharacter:
-    case NSNewlineCharacter:
-    case NSCarriageReturnCharacter:
-    case ' ':
-      [self fadeAwayInSlomo:([event modifierFlags] & NSShiftKeyMask) != 0];
-      break;
-    case '\e':  // Escape
-      tileSet_->set_selected_index(tabStripModel_->active_index());
-      [self fadeAwayInSlomo:([event modifierFlags] & NSShiftKeyMask) != 0];
-      break;
-  }
-}
-
-// Handle keyboard events that contain cmd or ctrl.
-- (BOOL)performKeyEquivalent:(NSEvent*)event {
-  if (state_ == tabpose::kFadingOut)
-    return NO;
-  NSString* characters = [event characters];
-  if ([characters length] < 1)
-    return NO;
-  unichar character = [characters characterAtIndex:0];
-  if ([event modifierFlags] & NSCommandKeyMask) {
-    if (character >= '1' && character <= '9') {
-      int index =
-          character == '9' ? tabStripModel_->count() - 1 : character - '1';
-      if (index < tabStripModel_->count()) {
-        tileSet_->set_selected_index(index);
-        [self fadeAwayInSlomo:([event modifierFlags] & NSShiftKeyMask) != 0];
-        return YES;
-      }
-    }
-  }
-  return NO;
-}
-
-- (void)flagsChanged:(NSEvent*)event {
-  showAllCloseLayers_ = ([event modifierFlags] & NSAlternateKeyMask) != 0;
-  [self updateClosebuttonLayersVisibility];
-}
-
-- (void)selectTileFromMouseEvent:(NSEvent*)event {
-  int newIndex = -1;
-  CGPoint p = NSPointToCGPoint([event locationInWindow]);
-  for (NSUInteger i = 0; i < [allThumbnailLayers_ count]; ++i) {
-    CALayer* layer = [allThumbnailLayers_ objectAtIndex:i];
-    CGPoint lp = [layer convertPoint:p fromLayer:rootLayer_];
-    if ([static_cast<CALayer*>([layer presentationLayer]) containsPoint:lp])
-      newIndex = i;
-  }
-  if (newIndex >= 0)
-    [self selectTileAtIndexWithoutAnimation:newIndex];
-}
-
-- (void)mouseMoved:(NSEvent*)event {
-  [self selectTileFromMouseEvent:event];
-}
-
-- (CALayer*)closebuttonLayerAtIndex:(NSUInteger)index {
-  CALayer* layer = [allThumbnailLayers_ objectAtIndex:index];
-  return [[layer sublayers] objectAtIndex:0];
-}
-
-- (void)updateClosebuttonLayersVisibility {
-  for (NSUInteger i = 0; i < [allThumbnailLayers_ count]; ++i) {
-    CALayer* layer = [self closebuttonLayerAtIndex:i];
-    BOOL isSelectedTile = static_cast<int>(i) == tileSet_->selected_index();
-    BOOL isVisible = state_ == tabpose::kFadedIn &&
-                     (isSelectedTile || showAllCloseLayers_);
-    layer.hidden = !isVisible;
-  }
-}
-
-- (void)mouseDown:(NSEvent*)event {
-  // Just in case the user clicked without ever moving the mouse.
-  [self selectTileFromMouseEvent:event];
-
-  // If the click occurred in a close box, close that tab and don't do anything
-  // else.
-  CGPoint p = NSPointToCGPoint([event locationInWindow]);
-  for (NSUInteger i = 0; i < [allThumbnailLayers_ count]; ++i) {
-    CALayer* layer = [self closebuttonLayerAtIndex:i];
-    CGPoint lp = [layer convertPoint:p fromLayer:rootLayer_];
-    if ([static_cast<CALayer*>([layer presentationLayer]) containsPoint:lp] &&
-        !layer.hidden) {
-      tabStripModel_->CloseWebContentsAt(i,
-          TabStripModel::CLOSE_USER_GESTURE |
-          TabStripModel::CLOSE_CREATE_HISTORICAL_TAB);
-      return;
-    }
-  }
-
-  [self fadeAwayInSlomo:([event modifierFlags] & NSShiftKeyMask) != 0];
-}
-
-- (void)swipeWithEvent:(NSEvent*)event {
-  if (abs([event deltaY]) > 0.5)  // Swipe up or down.
-    [self fadeAwayInSlomo:([event modifierFlags] & NSShiftKeyMask) != 0];
-}
-
-- (void)close {
-  // Prevent parent window from disappearing.
-  [[self parentWindow] removeChildWindow:self];
-
-  // We're dealloc'd in an autorelease pool – by then the observer registry
-  // might be dead, so explicitly reset the observer now.
-  tabStripModelObserverBridge_.reset();
-
-  [super close];
-}
-
-- (void)commandDispatch:(id)sender {
-  if ([sender tag] == IDC_TABPOSE)
-    [self fadeAwayInSlomo:NO];
-}
-
-- (BOOL)validateUserInterfaceItem:(id<NSValidatedUserInterfaceItem>)item {
-  // Disable all browser-related menu items except the tab overview toggle.
-  SEL action = [item action];
-  NSInteger tag = [item tag];
-  return action == @selector(commandDispatch:) && tag == IDC_TABPOSE;
-}
-
-- (void)fadeAwayTileAtIndex:(int)index {
-  const tabpose::Tile& tile = tileSet_->tile_at(index);
-  CALayer* layer = [allThumbnailLayers_ objectAtIndex:index];
-  // Add a delegate to one of the implicit animations to get a notification
-  // once the animations are done.
-  if (static_cast<int>(index) == tileSet_->selected_index()) {
-    CAAnimation* animation = [CAAnimation animation];
-    animation.delegate = self;
-    [animation setValue:kAnimationIdFadeOut forKey:kAnimationIdKey];
-    [layer addAnimation:animation forKey:@"frame"];
-  }
-
-  // Thumbnail.
-  layer.frame = NSRectToCGRect(
-      tile.GetStartRectRelativeTo(tileSet_->selected_tile()));
-
-  if (static_cast<int>(index) == tileSet_->selected_index()) {
-    // Redraw layer at big resolution, so that zoom-in isn't blocky.
-    [layer setNeedsDisplay];
-  }
-
-  // Title.
-  CALayer* faviconLayer = [allFaviconLayers_ objectAtIndex:index];
-  faviconLayer.frame = NSRectToCGRect(
-      tile.GetFaviconStartRectRelativeTo(tileSet_->selected_tile()));
-  faviconLayer.opacity = 0;
-
-  // Favicon.
-  // The |fontSize| cannot be animated directly, animate the layer's scale
-  // instead. |transform.scale| affects the rendered width, so keep the small
-  // bounds.
-  CALayer* titleLayer = [allTitleLayers_ objectAtIndex:index];
-  NSRect titleRect = tile.title_rect();
-  NSRect titleToRect =
-      tile.GetTitleStartRectRelativeTo(tileSet_->selected_tile());
-  CGFloat scale = NSWidth(titleToRect) / NSWidth(titleRect);
-  titleToRect.origin.x +=
-      NSWidth(titleRect) * scale * titleLayer.anchorPoint.x;
-  titleToRect.origin.y +=
-      NSHeight(titleRect) * scale * titleLayer.anchorPoint.y;
-  titleLayer.position = NSPointToCGPoint(titleToRect.origin);
-  [titleLayer setValue:[NSNumber numberWithDouble:scale]
-            forKeyPath:@"transform.scale"];
-  titleLayer.opacity = 0;
-}
-
-- (void)fadeAwayInSlomo:(BOOL)slomo {
-  if (state_ == tabpose::kFadingOut)
-    return;
-
-  state_ = tabpose::kFadingOut;
-  [self setAcceptsMouseMovedEvents:NO];
-
-  // Select chosen tab.
-  if (tileSet_->selected_index() < tabStripModel_->count()) {
-    tabStripModel_->ActivateTabAt(tileSet_->selected_index(),
-                                  /*user_gesture=*/true);
-  } else {
-    DCHECK_EQ(tileSet_->selected_index(), 0);
-  }
-
-  {
-    ScopedCAActionDisabler disableCAActions;
-
-    // Move the selected layer on top of all other layers.
-    [self selectedLayer].zPosition = 1;
-
-    selectionHighlight_.hidden = YES;
-    // Running animations with shadows is slow, so turn shadows off before
-    // running the exit animation.
-    for (CALayer* layer in allThumbnailLayers_.get())
-      layer.shadowOpacity = 0.0;
-
-    [self updateClosebuttonLayersVisibility];
-  }
-
-  // Animate layers out, all in one transaction.
-  CGFloat duration =
-      1.3 * kDefaultAnimationDuration * (slomo ? kSlomoFactor : 1);
-  ScopedCAActionSetDuration durationSetter(duration);
-  for (int i = 0; i < tabStripModel_->count(); ++i)
-    [self fadeAwayTileAtIndex:i];
-  AnimateCALayerOpacityFromTo(topGradient_, 1, 0, duration);
-}
-
-- (void)animationDidStop:(CAAnimation*)animation finished:(BOOL)finished {
-  NSString* animationId = [animation valueForKey:kAnimationIdKey];
-  if ([animationId isEqualToString:kAnimationIdFadeIn]) {
-    if (finished && state_ == tabpose::kFadingIn) {
-      // If the user clicks while the fade in animation is still running,
-      // |state_| is already kFadingOut. In that case, don't do anything.
-      state_ = tabpose::kFadedIn;
-
-      selectionHighlight_.hidden = NO;
-
-      // Running animations with shadows is slow, so turn shadows on only after
-      // the animation is done.
-      ScopedCAActionDisabler disableCAActions;
-      for (CALayer* layer in allThumbnailLayers_.get())
-        layer.shadowOpacity = 0.5;
-
-      [self updateClosebuttonLayersVisibility];
-    }
-  } else if ([animationId isEqualToString:kAnimationIdFadeOut]) {
-    DCHECK_EQ(tabpose::kFadingOut, state_);
-    [self close];
-  }
-}
-
-- (NSUInteger)thumbnailLayerCount {
-  return [allThumbnailLayers_ count];
-}
-
-- (int)selectedIndex {
-  return tileSet_->selected_index();
-}
-
-#pragma mark TabStripModelBridge
-
-- (void)refreshLayerFramesAtIndex:(int)i {
-  const tabpose::Tile& tile = tileSet_->tile_at(i);
-
-  CALayer* thumbLayer = [allThumbnailLayers_ objectAtIndex:i];
-
-  if (i == tileSet_->selected_index()) {
-    AnimateCALayerFrameFromTo(
-        selectionHighlight_,
-        NSInsetRect(NSRectFromCGRect(thumbLayer.frame),
-                    -kSelectionInset, -kSelectionInset),
-        NSInsetRect(tile.thumb_rect(),
-                    -kSelectionInset, -kSelectionInset),
-        kObserverChangeAnimationDuration,
-        nil);
-  }
-
-  // Repaint layer if necessary.
-  if (!NSEqualSizes(NSRectFromCGRect(thumbLayer.frame).size,
-                    tile.thumb_rect().size)) {
-    [thumbLayer setNeedsDisplay];
-  }
-
-  // Use AnimateCALayerFrameFromTo() instead of just setting |frame| to let
-  // the animation match the selection animation --
-  // |kCAMediaTimingFunctionDefault| is 10.6-only.
-  AnimateCALayerFrameFromTo(
-      thumbLayer,
-      NSRectFromCGRect(thumbLayer.frame),
-      tile.thumb_rect(),
-      kObserverChangeAnimationDuration,
-      nil);
-
-  CALayer* faviconLayer = [allFaviconLayers_ objectAtIndex:i];
-  AnimateCALayerFrameFromTo(
-      faviconLayer,
-      NSRectFromCGRect(faviconLayer.frame),
-      tile.favicon_rect(),
-      kObserverChangeAnimationDuration,
-      nil);
-
-  CALayer* titleLayer = [allTitleLayers_ objectAtIndex:i];
-  AnimateCALayerFrameFromTo(
-      titleLayer,
-      NSRectFromCGRect(titleLayer.frame),
-      tile.title_rect(),
-      kObserverChangeAnimationDuration,
-      nil);
-}
-
-- (void)insertTabWithContents:(content::WebContents*)contents
-                      atIndex:(NSInteger)index
-                 inForeground:(bool)inForeground {
-  // This happens if you cmd-click a link and then immediately open tabpose
-  // on a slowish machine.
-  ScopedCAActionSetDuration durationSetter(kObserverChangeAnimationDuration);
-
-  // Insert new layer and relayout.
-  tileSet_->InsertTileAt(index, contents);
-  tileSet_->Layout(containingRect_);
-  [self  addLayersForTile:tileSet_->tile_at(index)
-                 showZoom:NO
-                    slomo:NO
-        animationDelegate:nil];
-
-  // Update old layers.
-  DCHECK_EQ(tabStripModel_->count(),
-            static_cast<int>([allThumbnailLayers_ count]));
-  DCHECK_EQ(tabStripModel_->count(),
-            static_cast<int>([allTitleLayers_ count]));
-  DCHECK_EQ(tabStripModel_->count(),
-            static_cast<int>([allFaviconLayers_ count]));
-
-  // Update selection.
-  int selectedIndex = tileSet_->selected_index();
-  if (selectedIndex >= index)
-    selectedIndex++;
-  [self selectTileAtIndexWithoutAnimation:selectedIndex];
-
-  // Animate everything into its new place.
-  for (int i = 0; i < tabStripModel_->count(); ++i) {
-    if (i == index)  // The new layer.
-      continue;
-    [self refreshLayerFramesAtIndex:i];
-  }
-}
-
-- (void)tabClosingWithContents:(content::WebContents*)contents
-                       atIndex:(NSInteger)index {
-  // We will also get a -tabDetachedWithContents:atIndex: notification for
-  // closing tabs, so do nothing here.
-}
-
-- (void)tabDetachedWithContents:(content::WebContents*)contents
-                        atIndex:(NSInteger)index {
-  ScopedCAActionSetDuration durationSetter(kObserverChangeAnimationDuration);
-
-  // Remove layer and relayout.
-  tileSet_->RemoveTileAt(index);
-  tileSet_->Layout(containingRect_);
-
-  {
-    ScopedCAActionDisabler disabler;
-    [[allThumbnailLayers_ objectAtIndex:index] removeFromSuperlayer];
-    [allThumbnailLayers_ removeObjectAtIndex:index];
-    [[allTitleLayers_ objectAtIndex:index] removeFromSuperlayer];
-    [allTitleLayers_ removeObjectAtIndex:index];
-    [[allFaviconLayers_ objectAtIndex:index] removeFromSuperlayer];
-    [allFaviconLayers_ removeObjectAtIndex:index];
-  }
-
-  // Update old layers.
-  DCHECK_EQ(tabStripModel_->count(),
-            static_cast<int>([allThumbnailLayers_ count]));
-  DCHECK_EQ(tabStripModel_->count(),
-            static_cast<int>([allTitleLayers_ count]));
-  DCHECK_EQ(tabStripModel_->count(),
-            static_cast<int>([allFaviconLayers_ count]));
-
-  if (tabStripModel_->count() == 0)
-    [self close];
-
-  // Update selection.
-  int selectedIndex = tileSet_->selected_index();
-  if (selectedIndex > index || selectedIndex >= tabStripModel_->count())
-    selectedIndex--;
-  if (selectedIndex >= 0)
-    [self selectTileAtIndexWithoutAnimation:selectedIndex];
-
-  // Animate everything into its new place.
-  for (int i = 0; i < tabStripModel_->count(); ++i)
-    [self refreshLayerFramesAtIndex:i];
-}
-
-- (void)tabMovedWithContents:(content::WebContents*)contents
-                    fromIndex:(NSInteger)from
-                      toIndex:(NSInteger)to {
-  ScopedCAActionSetDuration durationSetter(kObserverChangeAnimationDuration);
-
-  // Move tile from |from| to |to|.
-  tileSet_->MoveTileFromTo(from, to);
-
-  // Move corresponding layers from |from| to |to|.
-  base::scoped_nsobject<CALayer> thumbLayer(
-      [[allThumbnailLayers_ objectAtIndex:from] retain]);
-  [allThumbnailLayers_ removeObjectAtIndex:from];
-  [allThumbnailLayers_ insertObject:thumbLayer.get() atIndex:to];
-  base::scoped_nsobject<CALayer> faviconLayer(
-      [[allFaviconLayers_ objectAtIndex:from] retain]);
-  [allFaviconLayers_ removeObjectAtIndex:from];
-  [allFaviconLayers_ insertObject:faviconLayer.get() atIndex:to];
-  base::scoped_nsobject<CALayer> titleLayer(
-      [[allTitleLayers_ objectAtIndex:from] retain]);
-  [allTitleLayers_ removeObjectAtIndex:from];
-  [allTitleLayers_ insertObject:titleLayer.get() atIndex:to];
-
-  // Update selection.
-  int selectedIndex = tileSet_->selected_index();
-  if (from == selectedIndex)
-    selectedIndex = to;
-  else if (from < selectedIndex && selectedIndex <= to)
-    selectedIndex--;
-  else if (to <= selectedIndex && selectedIndex < from)
-    selectedIndex++;
-  [self selectTileAtIndexWithoutAnimation:selectedIndex];
-
-  // Update frames of the layers.
-  for (int i = std::min(from, to); i <= std::max(from, to); ++i)
-    [self refreshLayerFramesAtIndex:i];
-}
-
-- (void)tabChangedWithContents:(content::WebContents*)contents
-                       atIndex:(NSInteger)index
-                    changeType:(TabStripModelObserver::TabChangeType)change {
-  // Tell the window to update text, title, and thumb layers at |index| to get
-  // their data from |contents|. |contents| can be different from the old
-  // contents at that index!
-  // While a tab is loading, this is unfortunately called quite often for
-  // both the "loading" and the "all" change types, so we don't really want to
-  // send thumb requests to the corresponding renderer when this is called.
-  // For now, just make sure that we don't hold on to an invalid WebContents
-  // object.
-  tabpose::Tile& tile = tileSet_->tile_at(index);
-  if (contents == tile.web_contents()) {
-    // TODO(thakis): Install a timer to send a thumb request/update title/update
-    // favicon after 20ms or so, and reset the timer every time this is called
-    // to make sure we get an updated thumb, without requesting them all over.
-    return;
-  }
-
-  tile.set_tab_contents(contents);
-  ThumbnailLayer* thumbLayer = [allThumbnailLayers_ objectAtIndex:index];
-  [thumbLayer setWebContents:contents];
-}
-
-- (void)tabStripModelDeleted {
-  [self close];
-}
-
-@end