[Fuchsia] Add web permissions in ApplicationConfig

Now cast_runner receives list of web permissions as part of the app
config and passes the list to the corresponding frame. This will be used
to enable microphone & camera access for apps that need it.

Bug: 922833
Change-Id: Ibae772c483a0389d3dee04722aeeb9e8c1b51015
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2084728
Commit-Queue: Sergey Ulanov <sergeyu@chromium.org>
Reviewed-by: Kevin Marshall <kmarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#746545}

fuchsia/fidl/cast/application_config.fidl

@@ -35,6 +35,9 @@ table ApplicationConfig {
 
   /// Simulates a different resolution for rendering.
   8: fuchsia.ui.gfx.vec2 force_content_dimensions;
+
+  /// List of the web permissions that should be granted to the application.
+  9: vector<fuchsia.web.PermissionDescriptor> permissions;
 };
 
 /// Service interface for working with application configurations.

fuchsia/runners/cast/cast_component.cc

@@ -86,6 +86,27 @@ void CastComponent::StartComponent() {
       frame(),
       agent_manager_->ConnectToAgentService<chromium::cast::ApplicationContext>(
           CastRunner::kAgentComponentUrl));
+
+  // Pass application permissions to the frame.
+  std::string origin = GURL(application_config_.web_url()).GetOrigin().spec();
+  if (application_config_.has_permissions()) {
+    for (auto& permission : application_config_.permissions()) {
+      fuchsia::web::PermissionDescriptor permission_clone;
+      zx_status_t status = permission.Clone(&permission_clone);
+      ZX_DCHECK(status == ZX_OK, status);
+      frame()->SetPermissionState(std::move(permission_clone), origin,
+                                  fuchsia::web::PermissionState::GRANTED);
+    }
+  } else {
+    // Grant PROTECTED_MEDIA_IDENTIFIER permission if permissions are not
+    // specified in the config. This is necessary for compatibility with older
+    // ApplicationConfigManager implementations that do not set permissions.
+    fuchsia::web::PermissionDescriptor eme_id_permission;
+    eme_id_permission.set_type(
+        fuchsia::web::PermissionType::PROTECTED_MEDIA_IDENTIFIER);
+    frame()->SetPermissionState(std::move(eme_id_permission), origin,
+                                fuchsia::web::PermissionState::GRANTED);
+  }
 }
 
 void CastComponent::DestroyComponent(int termination_exit_code,