refactor: unduplicate MediaStreamDevicesController (#34895)

* refactor: unduplicate MediaStreamDevicesController

* restore old logic for GUM_* request types

* lint

* gn format

* add test for unsupported getDisplayMedia

* simplify + comment

patches/chromium/short-circuit_permissions_checks_in_mediastreamdevicescontroller.patch

@@ -0,0 +1,88 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Jeremy Rose <japthorp@slack-corp.com>
+Date: Tue, 12 Jul 2022 16:51:43 -0700
+Subject: short-circuit permissions checks in MediaStreamDevicesController
+
+The //components/permissions architecture is complicated and not that
+widely used in Chromium, and mostly oriented around showing permissions
+UI and/or remembering per-site permissions, which we're not interested
+in.
+
+Since we do a permissions check prior to invoking the
+MediaStreamDevicesController, and don't (yet) provide the ability to set
+granular permissions (e.g. allow video but not audio), just
+short-circuit all the permissions checks in MSDC for now to allow us to
+unduplicate this code.
+
+diff --git a/components/webrtc/media_stream_devices_controller.cc b/components/webrtc/media_stream_devices_controller.cc
+index 353ed84da62b954a90c8d0a886495c0822f30429..1a1162ba960419a4de5eb2839ebc3debadca86d5 100644
+--- a/components/webrtc/media_stream_devices_controller.cc
++++ b/components/webrtc/media_stream_devices_controller.cc
+@@ -93,11 +93,14 @@ void MediaStreamDevicesController::RequestPermissions(
+ 
+   std::vector<blink::PermissionType> permission_types;
+ 
++#if 0
+   permissions::PermissionManager* permission_manager =
+       permissions::PermissionsClient::Get()->GetPermissionManager(
+           web_contents->GetBrowserContext());
++#endif
+ 
+   if (controller->ShouldRequestAudio()) {
++#if 0
+     permissions::PermissionResult permission_status =
+         permission_manager->GetPermissionStatusForCurrentDocument(
+             ContentSettingsType::MEDIASTREAM_MIC, rfh);
+@@ -109,10 +112,12 @@ void MediaStreamDevicesController::RequestPermissions(
+           permissions::PermissionStatusSource::FEATURE_POLICY);
+       return;
+     }
++#endif
+ 
+     permission_types.push_back(blink::PermissionType::AUDIO_CAPTURE);
+   }
+   if (controller->ShouldRequestVideo()) {
++#if 0
+     permissions::PermissionResult permission_status =
+         permission_manager->GetPermissionStatusForCurrentDocument(
+             ContentSettingsType::MEDIASTREAM_CAMERA, rfh);
+@@ -124,6 +129,7 @@ void MediaStreamDevicesController::RequestPermissions(
+           permissions::PermissionStatusSource::FEATURE_POLICY);
+       return;
+     }
++#endif
+ 
+     permission_types.push_back(blink::PermissionType::VIDEO_CAPTURE);
+ 
+@@ -135,6 +141,7 @@ void MediaStreamDevicesController::RequestPermissions(
+     // pan-tilt-zoom permission and there are suitable PTZ capable devices
+     // available.
+     if (request.request_pan_tilt_zoom_permission && has_pan_tilt_zoom_camera) {
++#if 0
+       permission_status =
+           permission_manager->GetPermissionStatusForCurrentDocument(
+               ContentSettingsType::CAMERA_PAN_TILT_ZOOM, rfh);
+@@ -144,6 +151,7 @@ void MediaStreamDevicesController::RequestPermissions(
+         controller->RunCallback(/*blocked_by_permissions_policy=*/false);
+         return;
+       }
++#endif
+ 
+       permission_types.push_back(blink::PermissionType::CAMERA_PAN_TILT_ZOOM);
+     }
+@@ -425,6 +433,7 @@ bool MediaStreamDevicesController::PermissionIsBlockedForReason(
+   if (rfh->GetLastCommittedOrigin().GetURL() != request_.security_origin) {
+     return false;
+   }
++#if 0
+   permissions::PermissionResult result =
+       permissions::PermissionsClient::Get()
+           ->GetPermissionManager(web_contents_->GetBrowserContext())
+@@ -433,6 +442,7 @@ bool MediaStreamDevicesController::PermissionIsBlockedForReason(
+     DCHECK_EQ(CONTENT_SETTING_BLOCK, result.content_setting);
+     return true;
+   }
++#endif
+   return false;
+ }
+