Fix tab restore for view-source Chrome extension pages.

content/public/browser/content_browser_client.h

 // Copyright (c) 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_CONTENT_BROWSER_CLIENT_H_
 #define CONTENT_PUBLIC_BROWSER_CONTENT_BROWSER_CLIENT_H_
 
 #include <stddef.h>
 
 #include <map>
@@ skipping 198 matching lines @@
   // isolation is enabled for this URL, and is a bug workaround.
   //
   // TODO(nick): Remove this function once https://crbug.com/160576 is fixed,
   // and origin lock can be applied to all URLs.
   virtual bool ShouldLockToOrigin(BrowserContext* browser_context,
                                   const GURL& effective_url);
 
   // Returns a list additional WebUI schemes, if any.  These additional schemes
   // act as aliases to the chrome: scheme.  The additional schemes may or may
   // not serve specific WebUI pages depending on the particular URLDataSource
-  // and its override of URLDataSource::ShouldServiceRequest. For all schemes
-  // returned here, view-source is allowed.
+  // and its override of URLDataSource::ShouldServiceRequest.
   virtual void GetAdditionalWebUISchemes(
       std::vector<std::string>* additional_schemes) {}
 
+  // Returns a list of additional schemes allowed for view-source.
+  virtual void GetAdditionalViewSourceSchemes(
+      std::vector<std::string>* additional_schemes) {}

[Charlie Reis, 2017/03/15 15:03:31]

I wonder if there's a risk that this breaks view-source in other content
embedders, like Opera?  They won't know to implement this right away, and
suddenly their WebUI schemes won't allow view-source.

It'd be a bit inconsistent with other methods in here, but we could make the
default implementation return GetAdditionalWebUISchemes (in the .cc file, plus
documented here) to avoid the issue.

[alexmos, 2017/03/16 20:07:30]

Good idea.  Done.

+
   // Called when WebUI objects are created to get aggregate usage data (i.e. is
   // chrome://downloads used more than chrome://bookmarks?). Only internal (e.g.
   // chrome://) URLs are logged. Returns whether the URL was actually logged.
   virtual bool LogWebUIUrl(const GURL& web_ui_url) const;
 
   // Returns whether a specified URL is handled by the embedder's internal
   // protocol handlers.
   virtual bool IsHandledURL(const GURL& url);
 
   // Returns whether the given process is allowed to commit |url|.  This is a
@@ skipping 590 matching lines @@
   virtual bool ShouldRedirectDOMStorageTaskRunner();
 
   // If this returns true, all BrowserThreads (but UI/IO) that support it on
   // this platform will experimentally be redirected to TaskScheduler.
   virtual bool RedirectNonUINonIOBrowserThreadsToTaskScheduler();
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_CONTENT_BROWSER_CLIENT_H_