Remove compat for iOS 7/8

BUG=None
R=magjed@webrtc.org, tkchin@webrtc.org

Review URL: https://codereview.webrtc.org/2382713002 .

Cr-Commit-Position: refs/heads/master@{#14448}
diff --git a/webrtc/modules/video_capture/ios/rtc_video_capture_ios_objc.mm b/webrtc/modules/video_capture/ios/rtc_video_capture_ios_objc.mm
index e36c83b..f12ff00 100644
--- a/webrtc/modules/video_capture/ios/rtc_video_capture_ios_objc.mm
+++ b/webrtc/modules/video_capture/ios/rtc_video_capture_ios_objc.mm
@@ -44,11 +44,8 @@
     _owner = owner;
     _captureId = captureId;
     _captureSession = [[AVCaptureSession alloc] init];
-#if defined(__IPHONE_7_0) && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_7_0
-    NSString* version = [[UIDevice currentDevice] systemVersion];
-    if ([version integerValue] >= 7) {
-      _captureSession.usesApplicationAudioSession = NO;
-    }
+#if defined(WEBRTC_IOS)
+    _captureSession.usesApplicationAudioSession = NO;
 #endif
     _captureChanging = NO;
     _captureChangingCondition = [[NSCondition alloc] init];
diff --git a/webrtc/modules/video_coding/codecs/h264/include/h264.h b/webrtc/modules/video_coding/codecs/h264/include/h264.h
index 54ad6eb..467845d 100644
--- a/webrtc/modules/video_coding/codecs/h264/include/h264.h
+++ b/webrtc/modules/video_coding/codecs/h264/include/h264.h
@@ -15,9 +15,8 @@
 #if defined(WEBRTC_IOS) || defined(WEBRTC_MAC)
 
 #include <Availability.h>
-#if (defined(__IPHONE_8_0) && defined(__IPHONE_OS_VERSION_MAX_ALLOWED) && \
-     __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_8_0) ||                  \
-    (defined(__MAC_10_8) && __MAC_OS_X_VERSION_MAX_ALLOWED >= __MAC_10_8)
+#if defined(WEBRTC_IOS) || \
+    defined(__MAC_10_8) && __MAC_OS_X_VERSION_MAX_ALLOWED >= __MAC_10_8
 #define WEBRTC_VIDEO_TOOLBOX_SUPPORTED 1
 #endif
 
diff --git a/webrtc/sdk/objc/Framework/Classes/avfoundationvideocapturer.mm b/webrtc/sdk/objc/Framework/Classes/avfoundationvideocapturer.mm
index 115f7f8..c71c9fd 100644
--- a/webrtc/sdk/objc/Framework/Classes/avfoundationvideocapturer.mm
+++ b/webrtc/sdk/objc/Framework/Classes/avfoundationvideocapturer.mm
@@ -412,14 +412,9 @@
 
 - (BOOL)setupCaptureSession {
   AVCaptureSession *captureSession = [[AVCaptureSession alloc] init];
-#if defined(__IPHONE_7_0) && defined(__IPHONE_OS_VERSION_MAX_ALLOWED) \
-    && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_7_0
-  NSString *version = [[UIDevice currentDevice] systemVersion];
-  if ([version integerValue] >= 7) {
-    captureSession.usesApplicationAudioSession = NO;
-  }
+#if defined(WEBRTC_IOS)
+  captureSession.usesApplicationAudioSession = NO;
 #endif
-
   // Add the output.
   AVCaptureVideoDataOutput *videoDataOutput = [self videoDataOutput];
   if (![captureSession canAddOutput:videoDataOutput]) {