New Public IdFromWebContents method on TabManager.

chrome/browser/memory/tab_manager_observer_browsertest.cc

 // Copyright (c) 2016 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 "base/macros.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/memory/tab_manager.h"
 #include "chrome/browser/memory/tab_manager_observer.h"
 #include "chrome/browser/memory/tab_manager_web_contents_data.h"
 #include "chrome/browser/ui/browser.h"
@@ skipping 19 matching lines @@
 
   int GetIndex(WebContents* contents) {
     return tab_strip_model_->GetIndexOfWebContents(contents);
   }
 
   WebContents* GetContents(int index) {
     return tab_strip_model_->GetWebContentsAt(index);
   }
 
   int64_t ContentsId(WebContents* contents) {
-    return reinterpret_cast<int64_t>(contents);
+    return TabManager::IdFromWebContents(contents);
   }
 
  private:
   TabStripModel* tab_strip_model_;
 };
 
 class MockTabManagerObserver : public TabManagerObserver {
  public:
   MockTabManagerObserver()
       : nb_events_(0),
@@ skipping 128 matching lines @@
   // Change it back and we should have another event.
   tab_manager->SetTabAutoDiscardableState(contents, true);
   EXPECT_EQ(2, observer.nb_events());
   EXPECT_TRUE(observer.is_auto_discardable());
   EXPECT_EQ(ContentsId(contents), ContentsId(observer.content()));
 }
 
 }  // namespace memory
 
 #endif  // OS_WIN || OS_MAXOSX || OS_LINUX