Clean up defensive TabManager handling

chrome/browser/ui/browser.cc

 // Copyright 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/ui/browser.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <string>
@@ skipping 1030 matching lines @@
   // focused object, which should happen before we update the toolbar below,
   // since the omnibox expects the correct element to already be focused when it
   // is updated.
   window_->OnActiveTabChanged(old_contents, new_contents, index, reason);
 
   exclusive_access_manager_->OnTabDetachedFromView(old_contents);
 
   // Discarded tabs always get reloaded.
   // TODO(georgesak): Validate the usefulness of this. And if needed then move
   // to TabManager.
-  if (g_browser_process->GetTabManager() &&
-      g_browser_process->GetTabManager()->IsTabDiscarded(new_contents))
+  if (g_browser_process->GetTabManager()->IsTabDiscarded(new_contents))
     chrome::Reload(this, CURRENT_TAB);
 
   // If we have any update pending, do it now.
   if (chrome_updater_factory_.HasWeakPtrs() && old_contents)
     ProcessPendingUIUpdates();
 
   // Propagate the profile to the location bar.
   UpdateToolbar((reason & CHANGE_REASON_REPLACED) == 0);
 
   if (search::IsInstantExtendedAPIEnabled())
@@ skipping 1538 matching lines @@
   if (contents && !allow_js_access) {
     contents->web_contents()->GetController().LoadURL(
         target_url,
         content::Referrer(),
         ui::PAGE_TRANSITION_LINK,
         std::string());  // No extra headers.
   }
 
   return contents != NULL;
 }