Add a postbuild action for executables built with ASan on Mac OS.

build/common.gypi

Index: build/common.gypi
===================================================================
--- build/common.gypi	(revision 173733)
+++ build/common.gypi	(working copy)
@@ -3421,6 +3421,31 @@
                 'xcode_settings': {
                   'CHROMIUM_STRIP_SAVE_FILE': '<(asan_saves_file)',
                 },
+                'postbuilds': [
+                  {
+                    # For executables built with ASan, copies the runtime lib
+                    # (libclang_rt.asan_osx_dynamic.dylib) on which they depend
+                    # from the compiler installation path to the build dir and
+                    # fixes the dylib's install name in the binary to be
+                    # relative to @executable_path. This is needed if the
+                    # executables are copied to a different machine (the ASan
+                    # runtime library must be copied in this case as well).
+                    'variables': {
+                      # Define change_mach_o_flags in a variable ending in _path

[Mark Mentovai, 2012/12/19 13:53:38]

If you’re using this, fix the comment.

+                      # so that GYP understands it's a path and performs proper
+                      # relativization during dict merging.
+                      'copy_asan_runtime_dylib_path':
+                          'mac/copy_asan_runtime_dylib.sh',
+                      'copy_asan_runtime_dylib_options%': [
+                      ],
+                    },
+                    'postbuild_name': 'Copy ASan runtime dylib',
+                    'action': [
+                      '<(copy_asan_runtime_dylib_path)',
+                      '>@(copy_asan_runtime_dylib_options)',
+                    ],
+                  },
+                ],
               }],
             ],
             'target_conditions': [