Add a "Simplify Page" option to the print preview dialog

chrome/browser/ui/tab_helpers.h

 // Copyright 2014 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.
 
 #ifndef CHROME_BROWSER_UI_TAB_HELPERS_H_
 #define CHROME_BROWSER_UI_TAB_HELPERS_H_
 
 namespace content {
 class WebContents;
 }
@@ skipping 32 matching lines @@
 
   // chrome::Navigate creates WebContents that are destined for the tab strip,
   // and that might have WebUI that immediately calls back into random tab
   // helpers.
   friend class BrowserNavigatorWebContentsAdoption;
 
   // Prerendering loads pages that have arbitrary external content; it needs
   // the full set of tab helpers to deal with it.
   friend class prerender::PrerenderContents;
 
+  // The print preview distiller needs to generate print previews,
+  // which is supported by tab helpers.

[Avi (use Gerrit), 2015/07/21 20:47:58]

But not *all* the tab helpers. Please explicitly add only the ones you need.

[arjunpatel, 2015/07/23 16:19:45]

Acknowledged.

+  friend class PrintPreviewDistiller;
+
   // Adopts the specified WebContents as a full-fledged browser tab, attaching
   // all the associated tab helpers that are needed for the WebContents to
   // serve in that role. It is safe to call this on a WebContents that was
   // already adopted.
   static void AttachTabHelpers(content::WebContents* web_contents);
 };
 
 #endif  // CHROME_BROWSER_UI_TAB_HELPERS_H_