Don't show a modal permission prompt if the requesting WebContents has no tab.

chrome/browser/permissions/permission_dialog_delegate.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_DIALOG_DELEGATE_H_
 #define CHROME_BROWSER_PERMISSIONS_PERMISSION_DIALOG_DELEGATE_H_
 
 #include <memory>
 
 #include "base/android/scoped_java_ref.h"
 #include "base/callback.h"
 #include "base/macros.h"
 #include "chrome/browser/permissions/permission_util.h"
 #include "content/public/browser/permission_type.h"
-#include "content/public/browser/web_contents_observer.h"
 
 using base::android::JavaParamRef;
 using base::android::ScopedJavaLocalRef;
 
 namespace content {
 class WebContents;
 }
 
 class MediaStreamDevicesController;
 class GURL;
 class PermissionInfoBarDelegate;
 class Profile;
+class TabAndroid;
 
 // Delegate class for displaying a permission prompt as a modal dialog. Used as
 // the native to Java interface to allow Java to communicate the user's
 // decision.
 //
 // This class currently wraps a PermissionInfoBarDelegate. Future refactoring
 // will consolidate PermissionInfoBarDelegate and its subclasses together into
 // GroupedPermissionInfoBarDelegate, which will then source all of its data from
 // an underlying PermissionPromptAndroid object. At that time, this class will
 // also change to wrap a PermissionPromptAndroid.
-class PermissionDialogDelegate : content::WebContentsObserver {
+class PermissionDialogDelegate {
  public:
   using PermissionSetCallback = base::Callback<void(bool, PermissionAction)>;
 
   // Creates a modal dialog for |type|.
   static void Create(content::WebContents* web_contents,
                      content::PermissionType type,
                      const GURL& requesting_frame,
                      bool user_gesture,
                      Profile* profile,
                      const PermissionSetCallback& callback);
@@ skipping 16 matching lines @@
   void Cancel(JNIEnv* env, const JavaParamRef<jobject>& obj, jboolean persist);
   void Dismissed(JNIEnv* env, const JavaParamRef<jobject>& obj);
   void LinkClicked(JNIEnv* env, const JavaParamRef<jobject>& obj);
 
   // Frees this object and the wrapped PermissionInfoBarDelegate. Called from
   // Java once the permission dialog has been responded to.
   void Destroy(JNIEnv* env, const JavaParamRef<jobject>& obj);
 
  private:
   PermissionDialogDelegate(
-      content::WebContents* web_contents,
+      TabAndroid* tab,
       std::unique_ptr<PermissionInfoBarDelegate> infobar_delegate_);
-  ~PermissionDialogDelegate() override;
+  ~PermissionDialogDelegate();
 
   ScopedJavaLocalRef<jobject> CreateJavaDelegate(JNIEnv* env);
 
+  TabAndroid* tab_;
+
   // The InfoBarDelegate which this class is wrapping.
   // TODO(dominickn,lshang) replace this with PermissionPromptAndroid as the
   // permission prompt refactoring continues.
   std::unique_ptr<PermissionInfoBarDelegate> infobar_delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(PermissionDialogDelegate);
 };
 
 #endif  // CHROME_BROWSER_PERMISSIONS_PERMISSION_DIALOG_DELEGATE_H_