Revert https://codereview.chromium.org/1291903002 (protobuf roll).

third_party/protobuf/objectivec/GPBWellKnownTypes.h

-// Protocol Buffers - Google's data interchange format
-// Copyright 2015 Google Inc.  All rights reserved.
-// https://developers.google.com/protocol-buffers/
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-#import <Foundation/Foundation.h>
-
-#import "google/protobuf/Any.pbobjc.h"
-#import "google/protobuf/Duration.pbobjc.h"
-#import "google/protobuf/Timestamp.pbobjc.h"
-
-
-NS_ASSUME_NONNULL_BEGIN
-
-// Extension to GPBTimestamp to work with standard Foundation time/date types.
-@interface GPBTimestamp (GBPWellKnownTypes)
-@property(nonatomic, readwrite, strong) NSDate *date;
-@property(nonatomic, readwrite) NSTimeInterval timeIntervalSince1970;
-- (instancetype)initWithDate:(NSDate *)date;
-- (instancetype)initWithTimeIntervalSince1970:(NSTimeInterval)timeIntervalSince1970;
-@end
-
-// Extension to GPBDuration to work with standard Foundation time type.
-@interface GPBDuration (GBPWellKnownTypes)
-@property(nonatomic, readwrite) NSTimeInterval timeIntervalSince1970;
-- (instancetype)initWithTimeIntervalSince1970:(NSTimeInterval)timeIntervalSince1970;
-@end
-
-// Extension to GPBAny to support packing and unpacking for arbitrary messages.
-@interface GPBAny (GPBWellKnownTypes)
-// Initialize GPBAny instance with the given message. e.g., for google.protobuf.foo, type
-// url will be "type.googleapis.com/google.protobuf.foo" and value will be serialized foo.
-- (instancetype)initWithMessage:(GPBMessage*)message;
-// Serialize the given message to the value in GPBAny. Type url will also be updated.
-- (void)setMessage:(GPBMessage*)message;
-// Parse the value in GPBAny to the given message. If messageClass message doesn't match the
-// type url in GPBAny, nil is returned.
-- (GPBMessage*)messageOfClass:(Class)messageClass;
-// True if the given type matches the type url in GPBAny.
-- (BOOL)wrapsMessageOfClass:(Class)messageClass;
-@end
-
-// Common prefix of type url in GPBAny, which is @"type.googleapis.com/". All valid
-// type urls in any should start with this prefix.
-extern NSString *const GPBTypeGoogleApisComPrefix;
-
-NS_ASSUME_NONNULL_END