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

third_party/protobuf/objectivec/GPBMessage_PackagePrivate.h

-// Protocol Buffers - Google's data interchange format
-// Copyright 2008 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.
-
-// This header is private to the ProtobolBuffers library and must NOT be
-// included by any sources outside this library. The contents of this file are
-// subject to change at any time without notice.
-
-#import "GPBMessage.h"
-
-#import <libkern/OSAtomic.h>
-
-#import "GPBBootstrap.h"
-
-typedef struct GPBMessage_Storage {
-  uint32_t _has_storage_[0];
-} GPBMessage_Storage;
-
-typedef struct GPBMessage_Storage *GPBMessage_StoragePtr;
-
-@interface GPBMessage () {
- @package
-  // NOTE: Because of the +allocWithZone code using NSAllocateObject(),
-  // this structure should ideally always be kept pointer aligned where the
-  // real storage starts is also pointer aligned. The compiler/runtime already
-  // do this, but it may not be documented.
-
-  // A pointer to the actual fields of the subclasses. The actual structure
-  // pointed to by this pointer will depend on the subclass.
-  // All of the actual structures will start the same as
-  // GPBMessage_Storage with _has_storage__ as the first field.
-  // Kept public because static functions need to access it.
-  GPBMessage_StoragePtr messageStorage_;
-
-  // A lock to provide mutual exclusion from internal data that can be modified
-  // by *read* operations such as getters (autocreation of message fields and
-  // message extensions, not setting of values). Used to guarantee thread safety
-  // for concurrent reads on the message.
-  OSSpinLock readOnlyMutex_;
-}
-
-// Gets an extension value without autocreating the result if not found. (i.e.
-// returns nil if the extension is not set)
-- (id)getExistingExtension:(GPBExtensionDescriptor *)extension;
-
-// Returns an array of GPBExtensionDescriptor* for all the extensions currently
-// in use on the message.  They are sorted by field number.
-- (NSArray *)sortedExtensionsInUse;
-
-// Parses a message of this type from the input and merges it with this
-// message.
-//
-// Warning:  This does not verify that all required fields are present in
-// the input message.
-// Note:  The caller should call
-// -[CodedInputStream checkLastTagWas:] after calling this to
-// verify that the last tag seen was the appropriate end-group tag,
-// or zero for EOF.
-// NOTE: This will throw if there is an error while parsing.
-- (void)mergeFromCodedInputStream:(GPBCodedInputStream *)input
-                extensionRegistry:(GPBExtensionRegistry *)extensionRegistry;
-
-// Parses the next delimited message of this type from the input and merges it
-// with this message.
-- (void)mergeDelimitedFromCodedInputStream:(GPBCodedInputStream *)input
-                         extensionRegistry:
-                             (GPBExtensionRegistry *)extensionRegistry;
-
-- (void)addUnknownMapEntry:(int32_t)fieldNum value:(NSData *)data;
-
-@end
-
-CF_EXTERN_C_BEGIN
-
-// Returns a new instance that was automatically created by |autocreator| for
-// its field |field|.
-GPBMessage *GPBCreateMessageWithAutocreator(Class msgClass,
-                                            GPBMessage *autocreator,
-                                            GPBFieldDescriptor *field)
-    __attribute__((ns_returns_retained));
-
-// Returns whether |message| autocreated this message. This is NO if the message
-// was not autocreated by |message| or if it has been mutated since
-// autocreation.
-BOOL GPBWasMessageAutocreatedBy(GPBMessage *message, GPBMessage *parent);
-
-// Call this when you mutate a message. It will cause the message to become
-// visible to its autocreator.
-void GPBBecomeVisibleToAutocreator(GPBMessage *self);
-
-// Call this when an array/dictionary is mutated so the parent message that
-// autocreated it can react.
-void GPBAutocreatedArrayModified(GPBMessage *self, id array);
-void GPBAutocreatedDictionaryModified(GPBMessage *self, id dictionary);
-
-// Clear the autocreator, if any. Asserts if the autocreator still has an
-// autocreated reference to this message.
-void GPBClearMessageAutocreator(GPBMessage *self);
-
-CF_EXTERN_C_END