Tabs being screen-captured will fullscreen within their tab contents area.

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"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #include <shellapi.h>
 #endif  // defined(OS_WIN)
@@ skipping 963 matching lines @@
   // Update the bookmark state, since the BrowserWindow may query it during
   // OnActiveTabChanged() below.
   UpdateBookmarkBarState(BOOKMARK_BAR_STATE_CHANGE_TAB_SWITCH);
 
   // Let the BrowserWindow do its handling.  On e.g. views this changes the
   // 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);
 
+  fullscreen_controller_->OnTabDetachedFromView(old_contents);
+
   // Discarded tabs always get reloaded.
   if (tab_strip_model_->IsTabDiscarded(index)) {
     LOG(WARNING) << "Reloading discarded tab at " << index;
     static int reload_count = 0;
     UMA_HISTOGRAM_CUSTOM_COUNTS(
         "Tabs.Discard.ReloadCount", ++reload_count, 1, 1000, 50);
     chrome::Reload(this, CURRENT_TAB);
   }
 
   // If we have any update pending, do it now.
@@ skipping 1306 matching lines @@
   if (contents && !allow_js_access) {
     contents->web_contents()->GetController().LoadURL(
         target_url,
         content::Referrer(),
         content::PAGE_TRANSITION_LINK,
         std::string());  // No extra headers.
   }
 
   return contents != NULL;
 }