media: Add MediaPermission interface and MediaPermissionDispatcher.

MediaPermission is the interface for media code to check/request media related
permissions. MediaPermissionDispatcher is a MediaPermission implementation in
content/.

Plan of follow-up CL:
- Use MediaPermission in ProxyDecryptor and remove current protected media
  identifier info bar code in the browser process (on Android and ChromeOS).

BUG=446263
TEST=Tested on Android with encrypted-media-requestmediakeysystemaccess.html
layout test by calling MediaPermission methods manually in
webencryptedmediaclient_impl.cc.

Review URL: https://codereview.chromium.org/871663003

Cr-Commit-Position: refs/heads/master@{#313303}

6 files changed, 77 insertions, 2 deletions

diff --git a/media/base/BUILD.gn b/media/base/BUILD.gn
index 9eedf1f..fd1bfe0 100644
--- a/media/base/BUILD.gn
+++ b/media/base/BUILD.gn
@@ -113,6 +113,8 @@ source_set("base") {
     "media_log.cc",
     "media_log.h",
     "media_log_event.h",
+    "media_permission.cc",
+    "media_permission.h",
     "media_switches.cc",
     "media_switches.h",
     "multi_channel_resampler.cc",
diff --git a/media/base/media_permission.cc b/media/base/media_permission.cc
new file mode 100644
index 0000000..739e445
--- /dev/null
+++ b/media/base/media_permission.cc
@@ -0,0 +1,15 @@
+// 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.
+
+#include "media/base/media_permission.h"
+
+namespace media {
+
+MediaPermission::MediaPermission() {
+}
+
+MediaPermission::~MediaPermission() {
+}
+
+}  // namespace media
diff --git a/media/base/media_permission.h b/media/base/media_permission.h
new file mode 100644
index 0000000..760ba0c
--- /dev/null
+++ b/media/base/media_permission.h
@@ -0,0 +1,49 @@
+// 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 MEDIA_BASE_MEDIA_PERMISSION_H_
+#define MEDIA_BASE_MEDIA_PERMISSION_H_
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "media/base/media_export.h"
+
+class GURL;
+
+namespace media {
+
+// Interface to handle media related permission checks and requests.
+class MEDIA_EXPORT MediaPermission {
+ public:
+  typedef base::Callback<void(bool)> PermissionStatusCB;
+
+  enum Type {
+    PROTECTED_MEDIA_IDENTIFIER,
+  };
+
+  MediaPermission();
+  virtual ~MediaPermission();
+
+  // Checks whether |type| is permitted for |security_origion| without
+  // triggering user interaction (e.g. permission prompt). The status will be
+  // |false| if the permission has never been set.
+  virtual void HasPermission(
+      Type type,
+      const GURL& security_origin,
+      const PermissionStatusCB& permission_status_cb) = 0;
+
+  // Requests |type| permission for |security_origion|. This may trigger user
+  // interaction (e.g. permission prompt) if the permission has never been set.
+  virtual void RequestPermission(
+      Type type,
+      const GURL& security_origin,
+      const PermissionStatusCB& permission_status_cb) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MediaPermission);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_BASE_MEDIA_PERMISSION_H_
diff --git a/media/blink/webencryptedmediaclient_impl.cc b/media/blink/webencryptedmediaclient_impl.cc
index dd1eaac..0050b43 100644
--- a/media/blink/webencryptedmediaclient_impl.cc
+++ b/media/blink/webencryptedmediaclient_impl.cc
@@ -8,6 +8,7 @@
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "media/base/key_systems.h"
+#include "media/base/media_permission.h"
 #include "net/base/mime_util.h"
 #include "third_party/WebKit/public/platform/WebEncryptedMediaRequest.h"
 #include "third_party/WebKit/public/platform/WebMediaKeySystemConfiguration.h"
@@ -131,8 +132,11 @@ static bool GetSupportedConfiguration(
 }
 
 WebEncryptedMediaClientImpl::WebEncryptedMediaClientImpl(
-    scoped_ptr<CdmFactory> cdm_factory)
+    scoped_ptr<CdmFactory> cdm_factory,
+    MediaPermission* /* media_permission */)
     : cdm_factory_(cdm_factory.Pass()) {
+  // TODO(sandersd): Use |media_permission| to check for media permissions in
+  // this class.
 }
 
 WebEncryptedMediaClientImpl::~WebEncryptedMediaClientImpl() {
diff --git a/media/blink/webencryptedmediaclient_impl.h b/media/blink/webencryptedmediaclient_impl.h
index 2b4e9d5..7aadfc2 100644
--- a/media/blink/webencryptedmediaclient_impl.h
+++ b/media/blink/webencryptedmediaclient_impl.h
@@ -13,10 +13,13 @@
 
 namespace media {
 
+class MediaPermission;
+
 class MEDIA_EXPORT WebEncryptedMediaClientImpl
     : public blink::WebEncryptedMediaClient {
  public:
-  WebEncryptedMediaClientImpl(scoped_ptr<CdmFactory> cdm_factory);
+  WebEncryptedMediaClientImpl(scoped_ptr<CdmFactory> cdm_factory,
+                              MediaPermission* media_permission);
   virtual ~WebEncryptedMediaClientImpl();
 
   // WebEncryptedMediaClient implementation.
diff --git a/media/media.gyp b/media/media.gyp
index 6fe8230..937e7ac 100644
--- a/media/media.gyp
+++ b/media/media.gyp
@@ -325,6 +325,8 @@
         'base/media_log.h',
         'base/media_log_event.h',
         'base/media_posix.cc',
+        'base/media_permission.cc',
+        'base/media_permission.h',
         'base/media_switches.cc',
         'base/media_switches.h',
         'base/media_win.cc',