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

third_party/protobuf/objectivec/GPBExtensionRegistry.m

Index: third_party/protobuf/objectivec/GPBExtensionRegistry.m
diff --git a/third_party/protobuf/objectivec/GPBExtensionRegistry.m b/third_party/protobuf/objectivec/GPBExtensionRegistry.m
deleted file mode 100644
index df61a17b187ab1d21894e0da8e4b33939491e935..0000000000000000000000000000000000000000
--- a/third_party/protobuf/objectivec/GPBExtensionRegistry.m
+++ /dev/null
@@ -1,108 +0,0 @@
-// 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.
-
-#import "GPBExtensionRegistry.h"
-
-#import "GPBBootstrap.h"
-#import "GPBDescriptor.h"
-
-@implementation GPBExtensionRegistry {
-  // TODO(dmaclach): Reimplement with CFDictionaries that don't use
-  // objects as keys.
-  NSMutableDictionary *mutableClassMap_;
-}
-
-- (instancetype)init {
-  if ((self = [super init])) {
-    mutableClassMap_ = [[NSMutableDictionary alloc] init];
-  }
-  return self;
-}
-
-- (void)dealloc {
-  [mutableClassMap_ release];
-  [super dealloc];
-}
-
-- (instancetype)copyWithZone:(NSZone *)zone {
-  GPBExtensionRegistry *result = [[[self class] allocWithZone:zone] init];
-  if (result && mutableClassMap_.count) {
-    [result->mutableClassMap_ addEntriesFromDictionary:mutableClassMap_];
-  }
-  return result;
-}
-
-- (NSMutableDictionary *)extensionMapForContainingMessageClass:
-        (Class)containingMessageClass {
-  NSMutableDictionary *extensionMap =
-      [mutableClassMap_ objectForKey:containingMessageClass];
-  if (extensionMap == nil) {
-    extensionMap = [NSMutableDictionary dictionary];
-    [mutableClassMap_ setObject:extensionMap
-                         forKey:(id<NSCopying>)containingMessageClass];
-  }
-  return extensionMap;
-}
-
-- (void)addExtension:(GPBExtensionDescriptor *)extension {
-  if (extension == nil) {
-    return;
-  }
-
-  Class containingMessageClass = extension.containingMessageClass;
-  NSMutableDictionary *extensionMap =
-      [self extensionMapForContainingMessageClass:containingMessageClass];
-  [extensionMap setObject:extension forKey:@(extension.fieldNumber)];
-}
-
-- (GPBExtensionDescriptor *)extensionForDescriptor:(GPBDescriptor *)descriptor
-                                       fieldNumber:(NSInteger)fieldNumber {
-  Class messageClass = descriptor.messageClass;
-  NSDictionary *extensionMap =
-      [mutableClassMap_ objectForKey:messageClass];
-  return [extensionMap objectForKey:@(fieldNumber)];
-}
-
-- (void)addExtensions:(GPBExtensionRegistry *)registry {
-  if (registry == nil) {
-    // In the case where there are no extensions just ignore.
-    return;
-  }
-  NSMutableDictionary *otherClassMap = registry->mutableClassMap_;
-  for (Class containingMessageClass in otherClassMap) {
-    NSMutableDictionary *extensionMap =
-        [self extensionMapForContainingMessageClass:containingMessageClass];
-    NSMutableDictionary *otherExtensionMap =
-        [registry extensionMapForContainingMessageClass:containingMessageClass];
-    [extensionMap addEntriesFromDictionary:otherExtensionMap];
-  }
-}
-
-@end