Remove WebContents::WasHidden() calls in chrome::AddRestoredTab() and TabLoader

chrome/browser/sessions/tab_loader.cc

 // Copyright 2015 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/sessions/tab_loader.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/memory/memory_pressure_monitor.h"
@@ skipping 156 matching lines @@
     }
 
     NavigationController* controller = tabs_to_load_.front();
     DCHECK(controller);
     tabs_loading_.insert(controller);
     tabs_to_load_.pop_front();
     controller->LoadIfNecessary();
     content::WebContents* contents = controller->GetWebContents();
     if (contents) {
       Browser* browser = chrome::FindBrowserWithWebContents(contents);
-      if (browser &&
-          browser->tab_strip_model()->GetActiveWebContents() != contents) {
-        // By default tabs are marked as visible. As only the active tab is
-        // visible we need to explicitly tell non-active tabs they are hidden.
-        // Without this call non-active tabs are not marked as backgrounded.
-        //
-        // NOTE: We need to do this here rather than when the tab is added to
-        // the Browser as at that time not everything has been created, so that
-        // the call would do nothing.
-        contents->WasHidden();
-      }
+      bool is_active = browser &&
+          browser->tab_strip_model()->GetActiveWebContents() == contents;
+
+      // Background tabs should have been loaded with WebContents::CreateParams
+      // initially_hidden = true. Ensure this is reflected in the tab status.
+      DCHECK_EQ(is_active, contents->GetRenderWidgetHostView()->IsShowing());
     }
   }
 
   if (!tabs_to_load_.empty())
     StartTimer();
 }
 
 void TabLoader::StartFirstTimer() {
   force_load_timer_.Stop();
   force_load_timer_.Start(FROM_HERE,
@@ skipping 69 matching lines @@
     // memory pressure.
     stats_collector_->DeferTab(tab);
   }
   // By calling |LoadNextTab| explicitly, we make sure that the
   // |NOTIFICATION_SESSION_RESTORE_DONE| event gets sent.
   LoadNextTab();
 }
 
 // static
 TabLoader* TabLoader::shared_tab_loader_ = nullptr;