Plugs in the new thumbnailing algorithm to ThumbnailTabHelper.

chrome/browser/thumbnails/thumbnail_service_impl.cc

Index: chrome/browser/thumbnails/thumbnail_service_impl.cc
diff --git a/chrome/browser/thumbnails/thumbnail_service_impl.cc b/chrome/browser/thumbnails/thumbnail_service_impl.cc
index 21f7227925edeb7253ad9e1f1d3f713835f11d28..ab3ef6273a8a2de41c9f51b5f33e55d473cb4cb3 100644
--- a/chrome/browser/thumbnails/thumbnail_service_impl.cc
+++ b/chrome/browser/thumbnails/thumbnail_service_impl.cc
@@ -4,10 +4,14 @@
 
 #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 {
 
@@ -15,12 +19,22 @@ namespace {
 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() {
@@ -47,7 +61,10 @@ bool ThumbnailServiceImpl::GetPageThumbnail(
 
 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) {
@@ -84,4 +101,4 @@ void ThumbnailServiceImpl::ShutdownOnUIThread() {
   top_sites_ = NULL;
 }
 
-}
+}  // namespace thumbnails