Plugs in the new thumbnailing algorithm to ThumbnailTabHelper.

chrome/browser/thumbnails/simple_thumbnail_crop.h

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_THUMBNAILS_SIMPLE_THUMBNAIL_CROP_H_
 #define CHROME_BROWSER_THUMBNAILS_SIMPLE_THUMBNAIL_CROP_H_
 
 #include "chrome/browser/thumbnails/thumbnailing_algorithm.h"
 
 namespace thumbnails {
 
 // The implementation of the 'classic' thumbnail cropping algorithm. It is not
 // content-driven in any meaningful way (save for score calculation). Rather,
 // the choice of a cropping region is based on relation between source and
 // target sizes. The selected source region is then rescaled into the target
 // thumbnail image.
 class SimpleThumbnailCrop : public ThumbnailingAlgorithm {
  public:
   explicit SimpleThumbnailCrop(const gfx::Size& target_size);
 
   virtual ClipResult GetCanvasCopyInfo(const gfx::Size& source_size,
                                        ui::ScaleFactor scale_factor,
                                        gfx::Rect* clipping_rect,
                                        gfx::Size* target_size) const OVERRIDE;
 
-  virtual void ProcessBitmap(ThumbnailingContext* context,
+  virtual void ProcessBitmap(scoped_refptr<ThumbnailingContext> context,
                              const ConsumerCallback& callback,
                              const SkBitmap& bitmap) OVERRIDE;
 
   // Calculates how "boring" a thumbnail is. The boring score is the
   // 0,1 ranged percentage of pixels that are the most common
   // luma. Higher boring scores indicate that a higher percentage of a
   // bitmap are all the same brightness.
   // Statically exposed for use by tests only.
   static double CalculateBoringScore(const SkBitmap& bitmap);
 
   // Gets the clipped bitmap from |bitmap| per the aspect ratio of the
   // desired width and the desired height. For instance, if the input
   // bitmap is vertically long (ex. 400x900) and the desired size is
   // square (ex. 100x100), the clipped bitmap will be the top half of the
   // input bitmap (400x400).
   // Statically exposed for use by tests only.
   static SkBitmap GetClippedBitmap(const SkBitmap& bitmap,
                                    int desired_width,
                                    int desired_height,
                                    thumbnails::ClipResult* clip_result);
   static gfx::Size GetCopySizeForThumbnail(ui::ScaleFactor scale_factor,
                                            const gfx::Size& thumbnail_size);
+  static gfx::Rect GetClippingRect(const gfx::Size& source_size,
+                                   const gfx::Size& desired_size,
+                                   ClipResult* clip_result);
+
+  // Computes the size of a thumbnail that should be stored in the database from
+  // |given_size| (expected to be the thumbnail size we would normally want to
+  // see). The returned size is expressed in pixels and is determined by
+  // bumping the resolution up to the maximum scale factor.
+  static gfx::Size ComputeTargetSizeAtMaximumScale(const gfx::Size& given_size);
 
  protected:
   virtual ~SimpleThumbnailCrop();
 
  private:
-  gfx::Size GetThumbnailSizeInPixel() const;
-  static gfx::Rect GetClippingRect(const gfx::Size& source_size,
-                                   const gfx::Size& desired_size,
-                                   ClipResult* clip_result);
   static SkBitmap CreateThumbnail(const SkBitmap& bitmap,
                                   const gfx::Size& desired_size,
                                   ClipResult* clip_result);
 
   const gfx::Size target_size_;
 
   DISALLOW_COPY_AND_ASSIGN(SimpleThumbnailCrop);
 };
 
 }
 
 #endif  // CHROME_BROWSER_THUMBNAILS_SIMPLE_THUMBNAIL_CROP_H_