Correct iOS build for latest Xcode beta.

base/ios/crb_protocol_observers_unittest.mm

Index: base/ios/crb_protocol_observers_unittest.mm
diff --git a/base/ios/crb_protocol_observers_unittest.mm b/base/ios/crb_protocol_observers_unittest.mm
index 5f1105122943f27143e484e30f400e422a576bf6..b10a51fde4054d4e0bc42153dfa86d09e51b68d9 100644
--- a/base/ios/crb_protocol_observers_unittest.mm
+++ b/base/ios/crb_protocol_observers_unittest.mm
@@ -4,6 +4,7 @@
 
 #import "base/ios/crb_protocol_observers.h"
 #include "base/ios/weak_nsobject.h"
+#include "base/logging.h"
 #include "base/mac/scoped_nsautorelease_pool.h"
 #include "base/mac/scoped_nsobject.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -36,10 +37,9 @@
 @end
 
 @interface TestMutateObserver : TestCompleteObserver
-
 - (instancetype)initWithObserver:(CRBProtocolObservers*)observer
     NS_DESIGNATED_INITIALIZER;
-
+- (instancetype)init NS_UNAVAILABLE;
 @end
 
 namespace {
@@ -258,6 +258,11 @@ TEST_F(CRBProtocolObserversTest, NestedMutateObservers) {
   __weak id _observers;
 }
 
+- (instancetype)init {
+  NOTREACHED();
+  return nil;
+}
+
 - (instancetype)initWithObserver:(CRBProtocolObservers*)observers {
   self = [super init];
   if (self) {