Re-enable stripping to produce an MH_DYLIB_STUB for closure_blocks_leopard_compat_stub

chrome/browser/mac/closure_blocks_leopard_compat.h

 // Copyright (c) 2011 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.
 
 #ifndef CHROME_BROWSER_MAC_CLOSURE_BLOCKS_LEOPARD_COMPAT_H_
 #define CHROME_BROWSER_MAC_CLOSURE_BLOCKS_LEOPARD_COMPAT_H_
 #pragma once
 
 // libclosure (blocks) compatibilty for Mac OS X 10.5 (Leopard)
 //
 // Background material:
 // http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/Blocks
 // http://opensource.apple.com/source/libclosure/libclosure-38/
 //
 // Leopard doesn't support blocks. Chrome supports Leopard. Chrome needs to use
 // blocks.
 //
 // In any file where you use blocks (any time you type ^{...}), you must
 // #include this file to ensure that the runtime symbols referenced by code
 // emitted by the compiler are marked for weak-import. This means that if
 // these symbols are not present at runtime, the program will still load, but
 // their values will be NULL.
 //
 // In any target (in the GYP sense) where you use blocks, you must also depend
 // on the closure_blocks_leopard_compat target to ensure that these symbols
 // will be available at link time, even when the 10.5 SDK is in use. This
-// This allows the continued use of the 10.5 SDK, which does not contain these
+// allows the continued use of the 10.5 SDK, which does not contain these
 // symbols.
 //
 // This does not relieve you of the responsibility to not use blocks on
 // Leopard. Because runtime support for Blocks still isn't present on that
 // operating system, the weak-imported symbols will have value 0 and attempts
 // to do anything meaningful with them will fail or crash. You must take care
 // not to enter any codepath that uses blocks on Leopard. The base::mac::IsOS*
 // family may be helpful.
 //
 // Although this scheme allows the use of the 10.5 SDK and 10.5 runtime in an
 // application that uses blocks, it is still necessary to use a compiler that
 // supports blocks. GCC 4.2 as shipped with Xcode 3.2 for Mac OS X 10.6
 // qualifies, as do sufficiently recent versions of clang. GCC 4.2 as shipped
 // with Xcode 3.1 for Mac OS X 10.5 does not qualify.
 
-// _NSConcreteGlobalBlock and _NSConcreteStackBlock are a private
-// implementation details of libclosure defined in
-// libclosure/libclosure-38/Block_private.h, but they're exposed from
-// libSystem as public symbols, and the block-enabled compiler will emit code
-// that references these symbols. Because the symbols aren't present in 10.5's
-// libSystem, they must be declared as weak imports in any file that uses
-// blocks. Any block-using file must #include this header to guarantee that
-// the symbols will show up in linked output as weak imports when compiling
-// for a 10.5 deployment target. Because the symbols are always present in
-// 10.6 and higher, they do not need to be a weak imports when the deployment
-// target is at least 10.6.
+// _NSConcreteGlobalBlock and _NSConcreteStackBlock are private implementation
+// details of libclosure defined in libclosure/libclosure-38/Block_private.h,
+// but they're exposed from libSystem as public symbols, and the block-enabled
+// compiler will emit code that references these symbols. Because the symbols
+// aren't present in 10.5's libSystem, they must be declared as weak imports
+// in any file that uses blocks. Any block-using file must #include this
+// header to guarantee that the symbols will show up in linked output as weak
+// imports when compiling for a 10.5 deployment target. Because the symbols
+// are always present in 10.6 and higher, they do not need to be a weak
+// imports when the deployment target is at least 10.6.
 //
 // Both GCC and clang emit references to these symbols, providing implicit
 // declarations as needed, but respecting any user declaration when present.
 // See gcc-5666.3/gcc/c-parser.c build_block_struct_initlist,
 // gcc-5666.3/gcc/cp/parser.c build_block_struct_initlist, and
 // clang-2.9/lib/CodeGen/CodeGenModule.cpp
 // CodeGenModule::getNSConcreteGlobalBlock() and
 // CodeGenModule::getNSConcreteStackBlock().
 
 #include <AvailabilityMacros.h>
 
 extern "C" {
 
 #if MAC_OS_X_VERSION_MIN_REQUIRED <= MAC_OS_X_VERSION_10_5  // DT <= 10.5
 #define MAYBE_WEAK_IMPORT __attribute__((weak_import))
 #else  // DT > 10.5
 #define MAYBE_WEAK_IMPORT
 #endif  // DT <= 10.5
 
 MAYBE_WEAK_IMPORT extern void* _NSConcreteGlobalBlock[32];
 MAYBE_WEAK_IMPORT extern void* _NSConcreteStackBlock[32];
 
 #undef MAYBE_WEAK_IMPORT
 
 }  // extern "C"
 
 #endif  // CHROME_BROWSER_MAC_CLOSURE_BLOCKS_LEOPARD_COMPAT_H_