Revert of Add unit tests for RTCMTLVideoView. (patchset #6 id:100001 of https://codereview.webrtc.org/2723903003/ )

Reason for revert:
This CL depends on a reverted CL.

Original issue's description:
> Add unit tests for RTCMTLVideoView.
>
> To properly test the functionality,  following changes  were needed
> - Make RTCMTLVideoView compiliable for all cpu architectures not just arm64.
> This is needed so that the test can run on any device and on simulator as well.
> - Refactor RTCMTLVideoView to have  mockable class methods.
> The unittest class, RTCMTLVideoViewTests was designed to provide easy transition
> to XCTest when the time comes for that.
> To transition to XCTest it would suffice to inherit from XCTestCase and remove
> the gtest methods.
>
> BUG=webrtc:7079
>
> Review-Url: https://codereview.webrtc.org/2723903003
> Cr-Commit-Position: refs/heads/master@{#17014}
> Committed: 0ebe0199ac

TBR=magjed@webrtc.org,denicija@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:7079

Review-Url: https://codereview.webrtc.org/2733953006
Cr-Commit-Position: refs/heads/master@{#17118}

webrtc/sdk/BUILD.gn

@@ -94,7 +94,6 @@ if (is_ios || is_mac) {
 
   rtc_static_library("rtc_sdk_peerconnection_objc") {
     sources = [
-      "objc/Framework/Classes/Metal/RTCMTLNV12Renderer.h",
       "objc/Framework/Classes/RTCAVFoundationVideoCapturerInternal.h",
       "objc/Framework/Classes/RTCAVFoundationVideoCapturerInternal.mm",
       "objc/Framework/Classes/RTCAVFoundationVideoSource+Private.h",
@@ -258,12 +257,6 @@ if (is_ios || is_mac) {
         "objc/Framework/UnitTests/RTCSessionDescriptionTest.mm",
         "objc/Framework/UnitTests/avformatmappertests.mm",
       ]
-      if (is_ios) {
-        sources += [ "objc/Framework/UnitTests/RTCMTLVideoViewTests.mm" ]
-        if (current_cpu != "arm64") {
-          sources += [ "objc/Framework/Classes/Metal/RTCMTLVideoView.m" ]
-        }
-      }
       deps = [
         ":rtc_sdk_peerconnection_objc",
         "//third_party/ocmock",

webrtc/sdk/objc/Framework/Classes/Metal/RTCMTLNV12Renderer.h

@@ -24,15 +24,6 @@
  * @param frame The frame to be rendered.
  */
 - (void)drawFrame:(RTCVideoFrame *)frame;
-
-/**
- * Sets the provided view as rendering destination if possible.
- *
- * If not possible method returns NO and callers of the method are responisble for performing
- * cleanups.
- */
-- (BOOL)addRenderingDestination:(__kindof UIView *)view;
-
 @end
 
 /**
@@ -40,4 +31,11 @@
  */
 @interface RTCMTLNV12Renderer : NSObject <RTCMTLRenderer>
 
+/**
+ * Sets the provided view as rendering destination if possible.
+ *
+ * If not possible method returns NO and callers of the method are responisble for performing
+ * cleanups.
+ */
+- (BOOL)addRenderingDestination:(__kindof MTKView *)view;
 @end

webrtc/sdk/objc/Framework/Classes/Metal/RTCMTLVideoView.m

@@ -18,18 +18,15 @@
 
 #import "RTCMTLNV12Renderer.h"
 
-// To avoid unreconized symbol linker errors, we're taking advantage of the objc runtime.
-// Linking errors occur when compiling for architectures that don't support Metal.
-#define MTKViewClass NSClassFromString(@"MTKView")
-#define RTCMTLNV12RendererClass NSClassFromString(@"RTCMTLNV12Renderer")
-
 @interface RTCMTLVideoView () <MTKViewDelegate>
-@property(nonatomic, strong) RTCMTLNV12Renderer *renderer;
+@property(nonatomic, strong) id<RTCMTLRenderer> renderer;
 @property(nonatomic, strong) MTKView *metalView;
 @property(atomic, strong) RTCVideoFrame *videoFrame;
 @end
 
-@implementation RTCMTLVideoView
+@implementation RTCMTLVideoView {
+  id<RTCMTLRenderer> _renderer;
+}
 
 @synthesize renderer = _renderer;
 @synthesize metalView = _metalView;
@@ -61,41 +58,11 @@
 #endif
 }
 
-+ (MTKView *)createMetalView:(CGRect)frame {
-  MTKView *view = [[MTKViewClass alloc] initWithFrame:frame];
-  return view;
-}
-
-+ (RTCMTLNV12Renderer *)createMetalRenderer {
-  RTCMTLNV12Renderer *renderer = [[RTCMTLNV12RendererClass alloc] init];
-  return renderer;
-}
-
 - (void)configure {
-  if (![RTCMTLVideoView isMetalAvailable]) {
+  if ([RTCMTLVideoView isMetalAvailable]) {
-    RTCLog("Metal unavailable");
+    _metalView = [[MTKView alloc] initWithFrame:self.bounds];
-    return;
-  }
-
-  _metalView = [RTCMTLVideoView createMetalView:self.bounds];
-  _renderer = [RTCMTLVideoView createMetalRenderer];
-
-  if ([self configureMetalRenderer]) {
-    [self configureMetalView];
-  } else {
-    _renderer = nil;
-    RTCLogError("Metal configuration falied.");
-  }
-}
-
-- (BOOL)configureMetalRenderer {
-  return [_renderer addRenderingDestination:_metalView];
-}
-
-- (void)configureMetalView {
-  if (_metalView) {
-    _metalView.delegate = self;
     [self addSubview:_metalView];
+    _metalView.delegate = self;
     _metalView.contentMode = UIViewContentModeScaleAspectFit;
     _metalView.translatesAutoresizingMaskIntoConstraints = NO;
     UILayoutGuide *margins = self.layoutMarginsGuide;
@@ -103,14 +70,20 @@
     [_metalView.bottomAnchor constraintEqualToAnchor:margins.bottomAnchor].active = YES;
     [_metalView.leftAnchor constraintEqualToAnchor:margins.leftAnchor].active = YES;
     [_metalView.rightAnchor constraintEqualToAnchor:margins.rightAnchor].active = YES;
-  }
-}
 
+    _renderer = [[RTCMTLNV12Renderer alloc] init];
+    if (![(RTCMTLNV12Renderer *)_renderer addRenderingDestination:_metalView]) {
+      _renderer = nil;
+    };
+  } else {
+    RTCLogError("Metal configuration falied.");
+  }
+}
 #pragma mark - MTKViewDelegate methods
 
 - (void)drawInMTKView:(nonnull MTKView *)view {
   NSAssert(view == self.metalView, @"Receiving draw callbacks from foreign instance.");
-  [self.renderer drawFrame:self.videoFrame];
+  [_renderer drawFrame:self.videoFrame];
 }
 
 - (void)mtkView:(MTKView *)view drawableSizeWillChange:(CGSize)size {
@@ -119,8 +92,8 @@
 #pragma mark - RTCVideoRenderer
 
 - (void)setSize:(CGSize)size {
-  self.metalView.drawableSize = size;
+  _metalView.drawableSize = size;
-  [self.metalView draw];
+  [_metalView draw];
 }
 
 - (void)renderFrame:(nullable RTCVideoFrame *)frame {

webrtc/sdk/objc/Framework/UnitTests/RTCMTLVideoViewTests.mm

@@ -1,168 +0,0 @@
-/*
- *  Copyright 2017 The WebRTC project authors. All Rights Reserved.
- *
- *  Use of this source code is governed by a BSD-style license
- *  that can be found in the LICENSE file in the root of the source
- *  tree. An additional intellectual property rights grant can be found
- *  in the file PATENTS.  All contributing project authors may
- *  be found in the AUTHORS file in the root of the source tree.
- */
-
-#import <Foundation/Foundation.h>
-#import <OCMock/OCMock.h>
-
-#include "webrtc/base/gunit.h"
-
-#include <Metal/RTCMTLNV12Renderer.h>
-#include <WebRTC/RTCMTLVideoView.h>
-
-// Extension of RTCMTLVideoView for testing purposes.
-@interface RTCMTLVideoView (Testing)
-@property(nonatomic, strong) id<RTCMTLRenderer> renderer;
-@property(nonatomic, strong) UIView* metalView;
-@property(atomic, strong) RTCVideoFrame* videoFrame;
-
-+ (BOOL)isMetalAvailable;
-+ (UIView*)createMetalView:(CGRect)frame;
-+ (id<RTCMTLRenderer>)createMetalRenderer;
-- (void)drawInMTKView:(id)view;
-@end
-
-@interface RTCMTLVideoViewTests : NSObject
-@property(nonatomic, strong) id classMock;
-@property(nonatomic, strong) id metalViewMock;
-@property(nonatomic, strong) id rendererMock;
-@end
-
-@implementation RTCMTLVideoViewTests
-
-@synthesize classMock = _classMock;
-@synthesize metalViewMock = _metalViewMock;
-@synthesize rendererMock = _rendererMock;
-
-- (void)setup {
-  self.classMock = OCMClassMock([RTCMTLVideoView class]);
-
-  self.metalViewMock = OCMClassMock([RTCMTLVideoViewTests class]);
-  // NOTE: OCMock doesen't provide modern syntax for -ignoringNonObjectArgs.
-  [[[[self.classMock stub] ignoringNonObjectArgs] andReturn:self.metalViewMock]
-      createMetalView:CGRectZero];
-
-  self.rendererMock = OCMProtocolMock(@protocol(RTCMTLRenderer));
-  OCMStub([self.classMock createMetalRenderer]).andReturn(self.rendererMock);
-}
-
-- (void)tearDown {
-  [self.classMock stopMocking];
-  [self.rendererMock stopMocking];
-  [self.metalViewMock stopMocking];
-  self.classMock = nil;
-  self.rendererMock = nil;
-  self.metalViewMock = nil;
-}
-
-- (void)testMetalConfigureNotExecuted {
-  // when
-  OCMStub([self.classMock isMetalAvailable]).andReturn(NO);
-  RTCMTLVideoView *realView = [[RTCMTLVideoView alloc] init];
-
-  // then
-  EXPECT_TRUE(realView.renderer == nil);
-  EXPECT_TRUE(realView.metalView == nil);
-}
-
-- (void)testMetalConfigureExecuted {
-  // given
-  OCMStub([self.classMock isMetalAvailable]).andReturn(YES);
-  OCMStub([self.rendererMock addRenderingDestination:self.metalViewMock])
-      .andReturn(NO);
-
-  // when
-  RTCMTLVideoView *realView = [[RTCMTLVideoView alloc] init];
-
-  // then
-  EXPECT_TRUE(realView.renderer == nil);
-  EXPECT_TRUE(realView.metalView != nil);
-}
-
-- (void)testMetalDrawCallback {
-  // given
-  OCMStub([self.classMock isMetalAvailable]).andReturn(NO);
-  OCMExpect([self.rendererMock drawFrame:[OCMArg any]]);
-  RTCMTLVideoView *realView = [[RTCMTLVideoView alloc] init];
-  realView.metalView = self.metalViewMock;
-  realView.renderer = self.rendererMock;
-
-  // when
-  [realView drawInMTKView:self.metalViewMock];
-
-  // then
-  [self.rendererMock verify];
-}
-
-- (void)testRTCVideoRenderNilFrameCallback {
-  // given
-  OCMStub([self.classMock isMetalAvailable]).andReturn(NO);
-  RTCMTLVideoView *realView = [[RTCMTLVideoView alloc] init];
-
-  // when
-  [realView renderFrame:nil];
-
-  // then
-  EXPECT_TRUE(realView.videoFrame == nil);
-}
-
-- (void)testRTCVideoRenderFrameCallback {
-  // given
-  OCMStub([self.classMock isMetalAvailable]).andReturn(NO);
-  RTCMTLVideoView *realView = [[RTCMTLVideoView alloc] init];
-  id frame = OCMClassMock([RTCVideoFrame class]);
-  realView.metalView = self.metalViewMock;
-  realView.renderer = self.rendererMock;
-  OCMExpect([self.rendererMock drawFrame:frame]);
-
-  // when
-  [realView renderFrame:frame];
-  [realView drawInMTKView:self.metalViewMock];
-
-  // then
-  EXPECT_EQ(realView.videoFrame, frame);
-  [self.rendererMock verify];
-}
-@end
-
-TEST(RTCMTLVideoViewTests, MetalConfigureNotExecuted) {
-  RTCMTLVideoViewTests *test = [[RTCMTLVideoViewTests alloc] init];
-  [test setup];
-  [test testMetalConfigureNotExecuted];
-  [test tearDown];
-}
-
-
-TEST(RTCMTLVideoViewTests, MetalConfigureExecuted) {
-  RTCMTLVideoViewTests *test = [[RTCMTLVideoViewTests alloc] init];
-  [test setup];
-  [test testMetalConfigureExecuted];
-  [test tearDown];
-}
-
-TEST(RTCMTLVideoViewTests, MetalDrawCallback) {
-  RTCMTLVideoViewTests *test = [[RTCMTLVideoViewTests alloc] init];
-  [test setup];
-  [test testMetalDrawCallback];
-  [test tearDown];
-}
-
-TEST(RTCMTLVideoViewTests, RTCVideoRenderNilFrameCallback) {
-  RTCMTLVideoViewTests *test = [[RTCMTLVideoViewTests alloc] init];
-  [test setup];
-  [test testRTCVideoRenderNilFrameCallback];
-  [test tearDown];
-}
-
-TEST(RTCMTLVideoViewTests, RTCVideoRenderFrameCallback) {
-  RTCMTLVideoViewTests *test = [[RTCMTLVideoViewTests alloc] init];
-  [test setup];
-  [test testRTCVideoRenderFrameCallback];
-  [test tearDown];
-}