Bug 1702898 - Remove some respondsToSelector checks that were only needed for old macOS versions. r=mac-reviewers,jgilbert,tnikkel,bradwerth

-[NSOpenGLContext pixelFormat] is 10.10+
-[NSScreen backingScaleFactor] is 10.7+
+[NSEvent isSwipeTrackingFromScrollEventsEnabled] is 10.7+

Differential Revision: https://phabricator.services.mozilla.com/D110772

gfx/gl/GLContextProviderCGL.mm

@@ -168,22 +168,13 @@ static bool IsSameGPU(CGOpenGLDisplayMask mask1, CGOpenGLDisplayMask mask2) {
   return !mask1 && !mask2;
 }
 
-static NSOpenGLPixelFormat* GetPixelFormatForContext(NSOpenGLContext* aContext) {
-  // -[NSOpenGLContext pixelFormat] is macOS 10.10+
-  if ([aContext respondsToSelector:@selector(pixelFormat)]) {
-    return [aContext pixelFormat];
-  }
-  return [[[NSOpenGLPixelFormat alloc]
-      initWithCGLPixelFormatObj:CGLGetPixelFormat([aContext CGLContextObj])] autorelease];
-}
-
 void GLContextCGL::MigrateToActiveGPU() {
   if (!mActiveGPUSwitchMayHaveOccurred.compareExchange(true, false)) {
     return;
   }
 
   CGOpenGLDisplayMask newPreferredDisplayMask = GetFreshContextDisplayMask();
-  NSOpenGLPixelFormat* pixelFormat = GetPixelFormatForContext(mContext);
+  NSOpenGLPixelFormat* pixelFormat = [mContext pixelFormat];
   GLint currentVirtualScreen = [mContext currentVirtualScreen];
   GLint currentDisplayMask = 0;
   [pixelFormat getValues:&currentDisplayMask

widget/cocoa/nsCocoaUtils.mm

@@ -725,12 +725,9 @@ bool nsCocoaUtils::HiDPIEnabled() {
       if ([desc objectForKey:NSDeviceIsScreen] == nil) {
         continue;
       }
-      CGFloat scale = [screen respondsToSelector:@selector(backingScaleFactor)]
-                          ? [screen backingScaleFactor]
-                          : 1.0;
       // Currently, we only care about differentiating "1.0" and "2.0",
       // so we set one of the two low bits to record which.
-      if (scale > 1.0) {
+      if ([screen backingScaleFactor] > 1.0) {
         scaleFactors |= 2;
       } else {
         scaleFactors |= 1;

widget/cocoa/nsLookAndFeel.mm

@@ -480,10 +480,7 @@ nsresult nsLookAndFeel::NativeGetInt(IntID aID, int32_t& aResult) {
       aResult = 0;
       break;
     case IntID::SwipeAnimationEnabled:
-      aResult = 0;
-      if ([NSEvent respondsToSelector:@selector(isSwipeTrackingFromScrollEventsEnabled)]) {
-        aResult = [NSEvent isSwipeTrackingFromScrollEventsEnabled];
-      }
+      aResult = NSEvent.isSwipeTrackingFromScrollEventsEnabled;
       break;
     case IntID::ContextMenuOffsetVertical:
       aResult = -6;