Plugs in the new thumbnailing algorithm to ThumbnailTabHelper.

chrome/browser/thumbnails/thumbnailing_context.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_THUMBNAILING_CONTEXT_H_
 #define CHROME_BROWSER_THUMBNAILS_THUMBNAILING_CONTEXT_H_
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/thumbnails/thumbnail_service.h"
 #include "chrome/common/thumbnail_score.h"
 #include "content/public/browser/web_contents.h"
+#include "ui/gfx/size.h"
 
 namespace thumbnails {
 
 // The result of clipping. This can be used to determine if the
 // generated thumbnail is good or not.
 enum ClipResult {
   // Clipping is not done yet.
   CLIP_RESULT_UNPROCESSED,
   // The source image is smaller.
   CLIP_RESULT_SOURCE_IS_SMALLER,
   // Wider than tall by twice or more, clip horizontally.
   CLIP_RESULT_MUCH_WIDER_THAN_TALL,
   // Wider than tall, clip horizontally.
   CLIP_RESULT_WIDER_THAN_TALL,
   // Taller than wide, clip vertically.
   CLIP_RESULT_TALLER_THAN_WIDE,
   // The source and destination aspect ratios are identical.
   CLIP_RESULT_NOT_CLIPPED,
+  // The source and destination are identical.
+  CLIP_RESULT_SOURCE_SAME_AS_TARGET,
 };
 
 // Holds the information needed for processing a thumbnail.
 struct ThumbnailingContext : base::RefCountedThreadSafe<ThumbnailingContext> {
   ThumbnailingContext(content::WebContents* web_contents,
                       ThumbnailService* receiving_service,
                       bool load_interrupted);
 
+  // Create an instance for use with unit tests.
+  static ThumbnailingContext* CreateThumbnailingContextForTest() {
+    return new ThumbnailingContext();
+  }
+
   scoped_refptr<ThumbnailService> service;
   GURL url;
   ClipResult clip_result;
+  gfx::Size requested_copy_size;
   ThumbnailScore score;
 
  private:
+  ThumbnailingContext();
   ~ThumbnailingContext();
+
   friend class base::RefCountedThreadSafe<ThumbnailingContext>;
 };
 
 }
 
 #endif  // CHROME_BROWSER_THUMBNAILS_THUMBNAILING_CONTEXT_H_