Remove RenderFrameHost pointer from ChooserController.

chrome/browser/usb/usb_chooser_context.h

 // 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.
 
 #ifndef CHROME_BROWSER_USB_USB_CHOOSER_CONTEXT_H_
 #define CHROME_BROWSER_USB_USB_CHOOSER_CONTEXT_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 31 matching lines @@
   void GrantDevicePermission(const GURL& requesting_origin,
                              const GURL& embedding_origin,
                              const std::string& guid);
 
   // Checks if |requesting_origin| (when embedded within |embedding_origin| has
   // access to a device with |device_info|.
   bool HasDevicePermission(const GURL& requesting_origin,
                            const GURL& embedding_origin,
                            scoped_refptr<const device::UsbDevice> device);
 
+  base::WeakPtr<UsbChooserContext> AsWeakPtr();

[msw, 2017/03/13 23:48:51]

optional nit: rename GetWeakPtr()?

[Reilly Grant (use Gerrit), 2017/03/14 20:44:10]

base::SupportsWeakPointer uses the name AsWeakPtr() which I think makes sense
for an object that vends weak pointers to itself.

+
  private:
   // ChooserContextBase implementation.
   bool IsValidObject(const base::DictionaryValue& object) override;
 
   // device::UsbService::Observer implementation.
   void OnDeviceRemoved(scoped_refptr<device::UsbDevice> device) override;
 
   bool is_incognito_;
   std::map<std::pair<GURL, GURL>, std::set<std::string>> ephemeral_devices_;
   device::UsbService* usb_service_;
   ScopedObserver<device::UsbService, device::UsbService::Observer> observer_;
+  base::WeakPtrFactory<UsbChooserContext> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(UsbChooserContext);
 };
 
 #endif  // CHROME_BROWSER_USB_USB_CHOOSER_CONTEXT_H_