Fix header map nextPowerOf2 method.

test/ios/framework/framework.gyp

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
   'targets': [
     {
       'target_name': 'iOSFramework',
       'type': 'shared_library',
       'mac_bundle': 1,
       'sources': [
         'iOSFramework/iOSFramework.h',
+        'iOSFramework/Thing.h',
+        'iOSFramework/Thing.m',
       ],
       'link_settings': {
         'libraries': [
           '$(SDKROOT)/System/Library/Frameworks/Foundation.framework',
           '$(SDKROOT)/System/Library/Frameworks/UIKit.framework',
         ],
       },
       'mac_framework_headers': [
+        # Using two headers here tests mac_tool.py NextGreaterPowerOf2.
         'iOSFramework/iOSFramework.h',
+        'iOSFramework/Thing.h',
       ],
       'mac_framework_dirs': [
         '$(SDKROOT)/../../Library/Frameworks',
       ],
       'xcode_settings': {
         'OTHER_CFLAGS': [
           '-fobjc-abi-version=2',
         ],
         'INFOPLIST_FILE': 'iOSFramework/Info.plist',
         'GCC_VERSION': 'com.apple.compilers.llvm.clang.1_0',
         'SDKROOT': 'iphoneos',
         'IPHONEOS_DEPLOYMENT_TARGET': '8.0',
         'CONFIGURATION_BUILD_DIR':'build/Default',
         'CODE_SIGN_IDENTITY[sdk=iphoneos*]': 'iPhone Developer',
       },
     },
   ],
 }