Move SessionID, CaptureVisibleTabFunction to WebContents.

chrome/browser/extensions/api/offscreen_tabs/offscreen_tabs_api.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/extensions/api/offscreen_tabs/offscreen_tabs_api.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/hash_tables.h"
@@ skipping 757 matching lines @@
     }
   }
 
   return true;
 }
 
 ToDataUrlOffscreenTabFunction::ToDataUrlOffscreenTabFunction() {}
 ToDataUrlOffscreenTabFunction::~ToDataUrlOffscreenTabFunction() {}
 
 bool ToDataUrlOffscreenTabFunction::GetTabToCapture(
-    WebContents** web_contents, TabContents** tab_contents) {
+    WebContents** web_contents) {
   int offscreen_tab_id;
   EXTENSION_FUNCTION_VALIDATE(args_->GetInteger(0, &offscreen_tab_id));
 
   // TODO(alexbost): We want to optimize this function in order to get more
   // image updates on the browser side. One improvement would be to implement
   // another hash map in order to get offscreen tabs in O(1).
   OffscreenTab* offscreen_tab = NULL;
   if (!GetMap()->GetOffscreenTab(
           offscreen_tab_id, this, &offscreen_tab, &error_))
     return false;
 
   *web_contents = offscreen_tab->web_contents();
-  *tab_contents = offscreen_tab->tab_contents();
   return true;
 }
 
 UpdateOffscreenTabFunction::UpdateOffscreenTabFunction() {}
 UpdateOffscreenTabFunction::~UpdateOffscreenTabFunction() {}
 
 bool UpdateOffscreenTabFunction::RunImpl() {
   int offscreen_tab_id;
   EXTENSION_FUNCTION_VALIDATE(args_->GetInteger(0, &offscreen_tab_id));
 
@@ skipping 37 matching lines @@
   // async case (when a "javascript": URL is sent to a tab).
   if (!is_async)
     SendResponse(true);
 
   return true;
 }
 
 void UpdateOffscreenTabFunction::PopulateResult() {
   // There's no result associated with this callback.
 }