Plugs in the new thumbnailing algorithm to ThumbnailTabHelper.

chrome/browser/thumbnails/thumbnail_service_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/thumbnails/thumbnail_service_impl.h"
 
+#include "base/command_line.h"
 #include "base/memory/ref_counted_memory.h"
 #include "chrome/browser/history/history_service.h"
+#include "chrome/browser/search/search.h"
+#include "chrome/browser/thumbnails/content_based_thumbnailing_algorithm.h"
 #include "chrome/browser/thumbnails/simple_thumbnail_crop.h"
 #include "chrome/browser/thumbnails/thumbnailing_context.h"
+#include "chrome/common/chrome_switches.h"
 
 namespace {
 
 // The thumbnail size in DIP.
 const int kThumbnailWidth = 212;
 const int kThumbnailHeight = 132;
 
+// True if thumbnail retargeting feature is enabled (Finch/flags).
+bool IsThumbnailRetargetingEnabled() {
+  if (!chrome::IsInstantExtendedAPIEnabled())
+    return false;
+
+  return CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kEnableThumbnailRetargeting);
+}
+
 }
 
 namespace thumbnails {
 
 ThumbnailServiceImpl::ThumbnailServiceImpl(Profile* profile)
-    : top_sites_(profile->GetTopSites()) {
+    : top_sites_(profile->GetTopSites()),
+      use_thumbnail_retargeting_(IsThumbnailRetargetingEnabled()){
 }
 
 ThumbnailServiceImpl::~ThumbnailServiceImpl() {
 }
 
 bool ThumbnailServiceImpl::SetPageThumbnail(const ThumbnailingContext& context,
                                             const gfx::Image& thumbnail) {
   scoped_refptr<history::TopSites> local_ptr(top_sites_);
   if (local_ptr.get() == NULL)
     return false;
 
   return local_ptr->SetPageThumbnail(context.url, thumbnail, context.score);
 }
 
 bool ThumbnailServiceImpl::GetPageThumbnail(
     const GURL& url,
     scoped_refptr<base::RefCountedMemory>* bytes) {
   scoped_refptr<history::TopSites> local_ptr(top_sites_);
   if (local_ptr.get() == NULL)
     return false;
 
   return local_ptr->GetPageThumbnail(url, bytes);
 }
 
 ThumbnailingAlgorithm* ThumbnailServiceImpl::GetThumbnailingAlgorithm()
     const {
-  return new SimpleThumbnailCrop(gfx::Size(kThumbnailWidth, kThumbnailHeight));
+  const gfx::Size thumbnail_size(kThumbnailWidth, kThumbnailHeight);
+  if (use_thumbnail_retargeting_)
+    return new ContentBasedThumbnailingAlgorithm(thumbnail_size);
+  return new SimpleThumbnailCrop(thumbnail_size);
 }
 
 bool ThumbnailServiceImpl::ShouldAcquirePageThumbnail(const GURL& url) {
   scoped_refptr<history::TopSites> local_ptr(top_sites_);
 
   if (local_ptr.get() == NULL)
     return false;
 
   // Skip if the given URL is not appropriate for history.
   if (!HistoryService::CanAddURL(url))
@@ skipping 16 matching lines @@
   return true;
 }
 
 void ThumbnailServiceImpl::ShutdownOnUIThread() {
   // Since each call uses its own scoped_refptr, we can just clear the reference
   // here by assigning null. If another call is completed, it added its own
   // reference.
   top_sites_ = NULL;
 }
 
-}
+}  // namespace thumbnails