pre-PR cleanup

// FREEBIE

Signal/src/ViewControllers/CallViewController.swift

@@ -8,7 +8,6 @@ import PromiseKit
 
 // TODO: Add category so that button handlers can be defined where button is created.
 // TODO: Ensure buttons enabled & disabled as necessary.
-//class CallViewController: OWSViewController, CallObserver, CallServiceObserver, RTCEAGLVideoViewDelegate {
 class CallViewController: OWSViewController, CallObserver, CallServiceObserver {
 
     let TAG = "[CallViewController]"
@@ -231,10 +230,9 @@ class CallViewController: OWSViewController, CallObserver, CallServiceObserver {
     }
 
     func createVideoViews() {
-        localVideoView = RTCCameraPreviewView()
         remoteVideoView = RemoteVideoView()
-
         remoteVideoView.isUserInteractionEnabled = false
+        localVideoView = RTCCameraPreviewView()
 
         remoteVideoView.isHidden = true
         localVideoView.isHidden = true

Signal/src/call/CallAudioService.swift

@@ -418,8 +418,11 @@ struct AudioSource: Hashable {
 
         guard let availableInputs = session.availableInputs else {
             // I'm not sure when this would happen.
-            // TODO this happens when the call ends (at leas ton iOS8)
-//            owsFail("No available inputs or inputs not ready")
+            if #available(iOS 9.0, *) {
+                // Fails on iOS8. We *could* remove this assert, but it might
+                // still be helfpul in catching a bug in a more used platform.
+                owsFail("No available inputs or inputs not ready")
+            }
             return [AudioSource.builtInSpeaker]
         }
 

Signal/src/views/RemoteVideoView.h

@@ -5,8 +5,8 @@
 #import <WebRTC/RTCVideoRenderer.h>
 
 /**
- * Drives the full screen remote video, this class is backed by either the modern MetalKit backed view on supported
- * systems or the leagacy EAGL view. MetalKit is supported on 64bit systems running iOS8 or newer.
+ * Drives the full screen remote video. This is *not* a swift class
+ * so we can take advantage of some compile time constants from WebRTC
  */
 @interface RemoteVideoView : UIView <RTCVideoRenderer>
 

Signal/src/views/RemoteVideoView.m

@@ -79,12 +79,13 @@ NS_ASSUME_NONNULL_BEGIN
         return self;
     }
 
+    // On iOS8: prints a message saying the feature is unavailable.
     if (!SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(9, 0)) {
         _videoRenderer = [NullVideoRenderer new];
     }
 
+    // On 64-bit, iOS9+: uses the MetalKit backed view for improved battery/rendering performance.
     if (_videoRenderer == nil) {
-// This class is defined in objc in order to access this compile time macro
 // Currently RTC only supports metal on 64bit machines
 #if defined(RTC_SUPPORTS_METAL)
     // RTCMTLVideoView requires the MTKView class, available in the iOS9+ MetalKit framework
@@ -94,7 +95,9 @@ NS_ASSUME_NONNULL_BEGIN
 #endif
     }
 
+    // On 32-bit: uses the legacy EAGL backed view.
     if (_videoRenderer == nil) {
+        OWSAssert(!__arm64__);
         RTCEAGLVideoView *eaglVideoView = [[RTCEAGLVideoView alloc] initWithFrame:CGRectZero];
         eaglVideoView.delegate = self;
         _videoRenderer = eaglVideoView;