Report if video capturing meets output protection requirement.

content/renderer/media/secure_display_link_tracker.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 CONTENT_RENDERER_MEDIA_SECURE_DISPLAY_LINK_TRACKER_H_
+#define CONTENT_RENDERER_MEDIA_SECURE_DISPLAY_LINK_TRACKER_H_
+
+#include <vector>
+
+// Tracks all connected links (video sinks / tracks), and reports if they are
+// all secure for video capturing.
+template <typename T>
+class SecureDisplayLinkTracker {
+ public:
+  SecureDisplayLinkTracker() {}
+  ~SecureDisplayLinkTracker() {}
+
+  void Add(T* link, bool is_link_secure);
+  void Remove(T* link);
+  void Update(T* link, bool is_link_secure);
+  bool is_capturing_secure() { return insecure_links_.empty(); }
+
+ private:
+  // Record every insecure links.
+  std::vector<T*> insecure_links_;
+};
+
+template <typename T>
+void SecureDisplayLinkTracker<T>::Add(T* link, bool is_link_secure) {
+  if (!is_link_secure)
+    insecure_links_.push_back(link);
+}
+
+template <typename T>
+void SecureDisplayLinkTracker<T>::Remove(T* link) {
+  for (auto it = insecure_links_.begin(); it != insecure_links_.end(); ++it) {
+    if (*it == link) {
+      insecure_links_.erase(it);
+      break;
+    }
+  }
+}
+
+template <typename T>
+void SecureDisplayLinkTracker<T>::Update(T* link, bool is_link_secure) {
+  for (auto it = insecure_links_.begin(); it != insecure_links_.end(); ++it) {
+    if (*it == link) {
+      if (is_link_secure)
+        insecure_links_.erase(it);
+      return;
+    }
+  }
+  if (!is_link_secure)
+    insecure_links_.push_back(link);
+}
+
+#endif  // CONTENT_RENDERER_MEDIA_SECURE_DISPLAY_LINK_TRACKER_H_