Enable loading native libraries with RTLD_DEEPBIND

base/native_library_mac.mm

Index: base/native_library_mac.mm
diff --git a/base/native_library_mac.mm b/base/native_library_mac.mm
index f2df0a711a436087c3ff15f99fa2406c3b9b8957..db770c6c374e8cf678d6f6f23bcdb58e60ba0e92 100644
--- a/base/native_library_mac.mm
+++ b/base/native_library_mac.mm
@@ -39,8 +39,9 @@ std::string NativeLibraryLoadError::ToString() const {
 }
 
 // static
-NativeLibrary LoadNativeLibrary(const FilePath& library_path,
-                                NativeLibraryLoadError* error) {
+NativeLibrary LoadNativeLibraryWithOptions(const FilePath& library_path,
+                                           const NativeLibraryOptions& options,

[Lei Zhang, 2016/08/25 23:08:58]

Do we want to DCHECK() |options| and see if anyone is trying to set it here?
Ditto for Windows. Or is that a bit of a pain for callers of
LoadNativeLibraryWithOptions() ?

If you went over this already, I'll admit again that I haven't been paying
attention.

[Ken Rockot(use gerrit already), 2016/08/25 23:20:42]

Indeed, we went over this already :) To summarize:

We have a CHECK on android since we're not sure of the behavior of dlopen()
there.

On other platforms where the DEEPBIND behavior is the default, the flag is
allowed but has no effect. The option is defined in such a way that it should be
neither confusing nor semantically incorrect when setting it has no net effect.

+                                           NativeLibraryLoadError* error) {
   // dlopen() etc. open the file off disk.
   if (library_path.Extension() == "dylib" || !DirectoryExists(library_path)) {
     void* dylib = dlopen(library_path.value().c_str(), RTLD_LAZY);