GN: Work on Mac module search path.

build/config/mac/BUILD.gn

Index: build/config/mac/BUILD.gn
diff --git a/build/config/mac/BUILD.gn b/build/config/mac/BUILD.gn
index b6db8e0b7104d6638ac1a001b137aa8d968faeb1..2ebf45872d12447d35f9e245412db782a89da8ae 100644
--- a/build/config/mac/BUILD.gn
+++ b/build/config/mac/BUILD.gn
@@ -18,5 +18,18 @@ config("sdk") {
 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.
   ]
 }