Support "learn more" link for EME in PermissionRequestManager code-path on Android

chrome/browser/permissions/permission_prompt_android.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_PERMISSIONS_PERMISSION_PROMPT_ANDROID_H_
 #define CHROME_BROWSER_PERMISSIONS_PERMISSION_PROMPT_ANDROID_H_
 
 #include <vector>
 
 #include "base/strings/string16.h"
 #include "chrome/browser/ui/permission_bubble/permission_prompt.h"
 #include "components/content_settings/core/common/content_settings_types.h"
+#include "url/gurl.h"
 
 namespace content {
 class WebContents;
 }
 
 class PermissionPromptAndroid : public PermissionPrompt {
  public:
   explicit PermissionPromptAndroid(content::WebContents* web_contents);
   ~PermissionPromptAndroid() override;
 
@@ skipping 12 matching lines @@
   void Accept();
   void Deny();
 
   size_t PermissionCount() const;
   bool ShouldShowPersistenceToggle() const;
   ContentSettingsType GetContentSettingType(size_t position) const;
   int GetIconIdForPermission(size_t position) const;
   base::string16 GetMessageText(size_t position) const;
   base::string16 GetMessageTextFragment(size_t position) const;
 
+  base::string16 GetLinkText() const;
+  GURL GetLinkURL() const;
+
  private:
   // PermissionPromptAndroid is owned by PermissionRequestManager, so it should
   // be safe to hold a raw WebContents pointer here because this class is
   // destroyed before the WebContents.
   content::WebContents* web_contents_;
   // |delegate_| is the PermissionRequestManager, which owns this object.
   Delegate* delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(PermissionPromptAndroid);
 };
 
 #endif  // CHROME_BROWSER_PERMISSIONS_PERMISSION_PROMPT_ANDROID_H_