Fixes for turning on offliner request.

chrome/browser/android/offline_pages/prerendering_loader.h

 // Copyright 2016 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_ANDROID_OFFLINE_PAGES_PRERENDERING_LOADER_H_
 #define CHROME_BROWSER_ANDROID_OFFLINE_PAGES_PRERENDERING_LOADER_H_
 
 #include <memory>
 
 #include "base/callback.h"
@@ skipping 28 matching lines @@
   ~PrerenderingLoader() override;
 
   // Loads a page in the background if possible and returns whether the
   // request was accepted. If so, the LoadPageCallback will be informed
   // of status. Only one load request may exist as a time. If a previous
   // request is still in progress it must be stopped before a new
   // request will be accepted. The callback may be called more than
   // once - first for a successful load and then if canceled after the
   // load (which may be from resources being reclaimed) at which point
   // the retrieved WebContents should no longer be used.
-  virtual bool LoadPage(const GURL& url, const LoadPageCallback& callback);
+  virtual bool LoadPage(const GURL& url, LoadPageCallback callback);

[Pete Williamson, 2016/06/08 17:32:16]

Generally speaking, we like to pass classes by pointer or reference unless they
are small (std::String is the typical example of a small class, with only one
pointer member).  I can understand if your code cannot hold onto a reference,
but would a pointer work?  If so, be sure to use unique_ptr if transferring
ownership, or a bald pointer if ownership is managed elsewhere (and document
that it is unowned).

[dougarnett, 2016/06/08 20:02:31]

Done - holding copy of callback, fixed param signature

 
   // Stops (completes or cancels) the load request. Must be called when
   // LoadPageCallback is done with consuming the contents. May be called
   // prior to LoadPageCallback in order to cancel the current request (in
   // which case the callback will not be run).
   // This loader should also be responsible for stopping offline
   // prerenders when Chrome is transitioned to foreground.
   virtual void StopLoading();
 
   // Returns whether prerendering is possible for this device's configuration
@@ skipping 57 matching lines @@
   // Callback to call when the active load request completes, fails, or is
   // canceled.
   LoadPageCallback callback_;
 
   DISALLOW_COPY_AND_ASSIGN(PrerenderingLoader);
 };
 
 }  // namespace offline_pages
 
 #endif  // CHROME_BROWSER_ANDROID_OFFLINE_PAGES_PRERENDERING_LOADER_H_