GN: Work on Mac module search path.

build/config/mac/BUILD.gn

 # Copyright (c) 2013 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.
 
 import("//build/config/sysroot.gni")
 
 config("sdk") {
   common_flags = [
     "-isysroot", sysroot,
     "-mmacosx-version-min=10.6"
   ]
 
   cflags = common_flags
   ldflags = common_flags
 }
 
 # On Mac, this is used for everything except static libraries.
 config("mac_dynamic_flags") {
   ldflags = [
     "-Wl,-search_paths_first",
+    "-L.",
+    # Path for loading shared libraries for unbundled binaries.
+    "-Wl,-rpath,@loader_path/.",
+    # Path for loading shared libraries for bundled binaries. Get back from
+    # Binary.app/Contents/MacOS.
+    "-Wl,-rpath,@loader_path/../../..",
   ]
 }
+
+# On Mac, this is used only for executables.

[Nico, 2014/03/03 21:18:09]

common.gypi says

                # Turn on position-independence (ASLR) for executables. When
                # PIE is on for the Chrome executables, the framework will
                # also be subject to ASLR.

which might be interesting to mention.

common.gypi also doesn't do this for valgrind builds – I guess you don't care
about valgrind yet?

+config("mac_executable_flags") {
+  ldflags = [
+    "-Wl,-pie",  # Position independent.
+  ]
+}