Wrap WebRTC OBJC API types with RTC_OBJC_TYPE.

This CL introduced 2 new macros that affect the WebRTC OBJC API symbols:

- RTC_OBJC_TYPE_PREFIX:
  Macro used to prepend a prefix to the API types that are exported with
  RTC_OBJC_EXPORT.

  Clients can patch the definition of this macro locally and build
  WebRTC.framework with their own prefix in case symbol clashing is a
  problem.

  This macro must only be defined by changing the value in
  sdk/objc/base/RTCMacros.h  and not on via compiler flag to ensure
  it has a unique value.

- RCT_OBJC_TYPE:
  Macro used internally to reference API types. Declaring an API type
  without using this macro will not include the declared type in the
  set of types that will be affected by the configurable
  RTC_OBJC_TYPE_PREFIX.

Manual changes:
https://webrtc-review.googlesource.com/c/src/+/173781/5..10

The auto-generated changes in PS#5 have been done with:
https://webrtc-review.googlesource.com/c/src/+/174061.

Bug: None
Change-Id: I0d54ca94db764fb3b6cb4365873f79e14cd879b8
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/173781
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31153}

sdk/objc/components/renderer/opengl/RTCEAGLVideoView.m

@@ -21,7 +21,7 @@
 #import "base/RTCVideoFrameBuffer.h"
 #import "components/video_frame_buffer/RTCCVPixelBuffer.h"
 
-// RTCEAGLVideoView wraps a GLKView which is setup with
+// RTC_OBJC_TYPE(RTCEAGLVideoView) wraps a GLKView which is setup with
 // enableSetNeedsDisplay = NO for the purpose of gaining control of
 // exactly when to call -[GLKView display]. This need for extra
 // control is required to avoid triggering method calls on GLKView
@@ -30,23 +30,24 @@
 // error GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT. -[GLKView display] is
 // the method that will trigger the binding of the render
 // buffer. Because the standard behaviour of -[UIView setNeedsDisplay]
-// is disabled for the reasons above, the RTCEAGLVideoView maintains
+// is disabled for the reasons above, the RTC_OBJC_TYPE(RTCEAGLVideoView) maintains
 // its own |isDirty| flag.
 
-@interface RTCEAGLVideoView () <GLKViewDelegate>
-// |videoFrame| is set when we receive a frame from a worker thread and is read
-// from the display link callback so atomicity is required.
-@property(atomic, strong) RTCVideoFrame *videoFrame;
+@interface RTC_OBJC_TYPE (RTCEAGLVideoView)
+()<GLKViewDelegate>
+    // |videoFrame| is set when we receive a frame from a worker thread and is read
+    // from the display link callback so atomicity is required.
+    @property(atomic, strong) RTC_OBJC_TYPE(RTCVideoFrame) * videoFrame;
 @property(nonatomic, readonly) GLKView *glkView;
 @end
 
-@implementation RTCEAGLVideoView {
+@implementation RTC_OBJC_TYPE (RTCEAGLVideoView) {
   RTCDisplayLinkTimer *_timer;
   EAGLContext *_glContext;
   // This flag should only be set and read on the main thread (e.g. by
   // setNeedsDisplay)
   BOOL _isDirty;
-  id<RTCVideoViewShading> _shader;
+  id<RTC_OBJC_TYPE(RTCVideoViewShading)> _shader;
   RTCNV12TextureCache *_nv12TextureCache;
   RTCI420TextureCache *_i420TextureCache;
   // As timestamps should be unique between frames, will store last
@@ -67,7 +68,7 @@
   return [self initWithCoder:aDecoder shader:[[RTCDefaultShader alloc] init]];
 }
 
-- (instancetype)initWithFrame:(CGRect)frame shader:(id<RTCVideoViewShading>)shader {
+- (instancetype)initWithFrame:(CGRect)frame shader:(id<RTC_OBJC_TYPE(RTCVideoViewShading)>)shader {
   if (self = [super initWithFrame:frame]) {
     _shader = shader;
     if (![self configure]) {
@@ -77,7 +78,8 @@
   return self;
 }
 
-- (instancetype)initWithCoder:(NSCoder *)aDecoder shader:(id<RTCVideoViewShading>)shader {
+- (instancetype)initWithCoder:(NSCoder *)aDecoder
+                       shader:(id<RTC_OBJC_TYPE(RTCVideoViewShading)>)shader {
   if (self = [super initWithCoder:aDecoder]) {
     _shader = shader;
     if (![self configure]) {
@@ -127,11 +129,11 @@
   // Frames are received on a separate thread, so we poll for current frame
   // using a refresh rate proportional to screen refresh frequency. This
   // occurs on the main thread.
-  __weak RTCEAGLVideoView *weakSelf = self;
+  __weak RTC_OBJC_TYPE(RTCEAGLVideoView) *weakSelf = self;
   _timer = [[RTCDisplayLinkTimer alloc] initWithTimerHandler:^{
-      RTCEAGLVideoView *strongSelf = weakSelf;
-      [strongSelf displayLinkTimerDidFire];
-    }];
+    RTC_OBJC_TYPE(RTCEAGLVideoView) *strongSelf = weakSelf;
+    [strongSelf displayLinkTimerDidFire];
+  }];
   if ([[UIApplication sharedApplication] applicationState] == UIApplicationStateActive) {
     [self setupGL];
   }
@@ -182,7 +184,7 @@
 - (void)glkView:(GLKView *)view drawInRect:(CGRect)rect {
   // The renderer will draw the frame to the framebuffer corresponding to the
   // one used by |view|.
-  RTCVideoFrame *frame = self.videoFrame;
+  RTC_OBJC_TYPE(RTCVideoFrame) *frame = self.videoFrame;
   if (!frame || frame.timeStampNs == _lastDrawnFrameTimeStampNs) {
     return;
   }
@@ -192,7 +194,7 @@
   }
   [self ensureGLContext];
   glClear(GL_COLOR_BUFFER_BIT);
-  if ([frame.buffer isKindOfClass:[RTCCVPixelBuffer class]]) {
+  if ([frame.buffer isKindOfClass:[RTC_OBJC_TYPE(RTCCVPixelBuffer) class]]) {
     if (!_nv12TextureCache) {
       _nv12TextureCache = [[RTCNV12TextureCache alloc] initWithContext:_glContext];
     }
@@ -223,18 +225,18 @@
   }
 }
 
-#pragma mark - RTCVideoRenderer
+#pragma mark - RTC_OBJC_TYPE(RTCVideoRenderer)
 
 // These methods may be called on non-main thread.
 - (void)setSize:(CGSize)size {
-  __weak RTCEAGLVideoView *weakSelf = self;
+  __weak RTC_OBJC_TYPE(RTCEAGLVideoView) *weakSelf = self;
   dispatch_async(dispatch_get_main_queue(), ^{
-    RTCEAGLVideoView *strongSelf = weakSelf;
+    RTC_OBJC_TYPE(RTCEAGLVideoView) *strongSelf = weakSelf;
     [strongSelf.delegate videoView:strongSelf didChangeVideoSize:size];
   });
 }
 
-- (void)renderFrame:(RTCVideoFrame *)frame {
+- (void)renderFrame:(RTC_OBJC_TYPE(RTCVideoFrame) *)frame {
   self.videoFrame = frame;
 }