<webview> Implement clear http cache API.

chrome/browser/guest_view/web_view/chrome_web_view_guest_delegate.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_GUEST_VIEW_WEB_VIEW_CHROME_WEB_VIEW_GUEST_DELEGATE_H_
 #define CHROME_BROWSER_GUEST_VIEW_WEB_VIEW_CHROME_WEB_VIEW_GUEST_DELEGATE_H_
 
 #include "chrome/browser/extensions/api/web_view/chrome_web_view_internal_api.h"
 #include "extensions/browser/guest_view/web_view/web_view_guest.h"
 #include "extensions/browser/guest_view/web_view/web_view_guest_delegate.h"
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/chromeos/accessibility/accessibility_manager.h"
 #endif
 
 class RenderViewContextMenuBase;
 
 namespace ui {
 class SimpleMenuModel;
 }  // namespace ui
 
 namespace extensions {
 
 class ChromeWebViewGuestDelegate : public WebViewGuestDelegate {
  public :
   explicit ChromeWebViewGuestDelegate(WebViewGuest* web_view_guest);
   ~ChromeWebViewGuestDelegate() override;
 
   // WebViewGuestDelegate implementation.
+  void ClearCache(base::Time remove_since,
+                  const base::Closure& done_callback) override;
   bool HandleContextMenu(const content::ContextMenuParams& params) override;
   void OnAttachWebViewHelpers(content::WebContents* contents) override;
   void OnDidCommitProvisionalLoadForFrame(bool is_main_frame) override;
   void OnDidInitialize() override;
   void OnDocumentLoadedInFrame(
       content::RenderFrameHost* render_frame_host) override;
   void OnGuestDestroyed() override;
   void OnShowContextMenu(int request_id, const MenuItemVector* items) override;
 
   WebViewGuest* web_view_guest() const { return web_view_guest_; }
@@ skipping 38 matching lines @@
   // destroyed.
   base::WeakPtrFactory<ChromeWebViewGuestDelegate> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeWebViewGuestDelegate);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_GUEST_VIEW_WEB_VIEW_CHROME_WEB_VIEW_GUEST_DELEGATE_H_