diff --git a/base/mac/sdk_forward_declarations.h b/base/mac/sdk_forward_declarations.h
index 972a0cc..818a1d0 100644
--- a/base/mac/sdk_forward_declarations.h
+++ b/base/mac/sdk_forward_declarations.h
@@ -77,18 +77,6 @@
 
 #endif  // MAC_OS_X_VERSION_10_9
 
-#if !defined(MAC_OS_X_VERSION_10_10) || \
-    MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_10
-
-@interface NSUserActivity : NSObject
-@end
-
-#else
-
-@class NSUserActivity;
-
-#endif  // MAC_OS_X_VERSION_10_10
-
 // ----------------------------------------------------------------------------
 // Define typedefs, enums, and protocols not available in the version of the
 // OSX SDK being compiled against.
@@ -502,18 +490,6 @@
 #if !defined(MAC_OS_X_VERSION_10_10) || \
     MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_10
 
-@interface NSUserActivity (YosemiteSDK)
-
-@property(readonly, copy) NSString* activityType;
-@property(copy) NSDictionary* userInfo;
-@property(copy) NSURL* webpageURL;
-
-- (instancetype)initWithActivityType:(NSString*)activityType;
-- (void)becomeCurrent;
-- (void)invalidate;
-
-@end
-
 @interface CBUUID (YosemiteSDK)
 - (NSString*)UUIDString;
 @end