Fix up PathProvider on the Mac for FILE_MODULE.

base/base_paths_mac.mm

 // Copyright (c) 2006-2008 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.
 
 #include "base/base_paths_mac.h"
 
+#include <dlfcn.h>
 #import <Foundation/Foundation.h>
 #include <mach-o/dyld.h>
 
 #include "base/compiler_specific.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/mac/mac_util.h"
 #include "base/path_service.h"
 #include "base/string_util.h"
@@ skipping 13 matching lines @@
   char* executable_path_c = WriteInto(&executable_path, executable_length);
   int rv = _NSGetExecutablePath(executable_path_c, &executable_length);
   DCHECK_EQ(rv, 0);
   DCHECK(!executable_path.empty());
   if ((rv != 0) || (executable_path.empty()))
     return false;
   *path = FilePath(executable_path);
   return true;
 }
 
+// Returns true if the module for |address| is found. |path| will contain
+// the path to the module. Note that |path| may not be absolute.
+bool GetModulePathForAddress(FilePath* path,
+                             const void* address) WARN_UNUSED_RESULT;
+
+bool GetModulePathForAddress(FilePath* path, const void* address) {
+  Dl_info info;
+  if (dladdr(address, &info) == 0)

[Nico, 2011/09/05 23:15:00]

This call adds 0.1s to InProcessBrowserTest.Empty (which takes ~1.2, so it's
8%). This cost has to be paid for every single ui and browser test we run. There
are 440 of them, so this slows down try jobs 45s – on good days, 1.25% of total
try job time. Can you think of a way to not need this call?

(Also, putting mesa.so into the bundle shows up on the chromium size graph even
though it's not shipped to users, which is a bit confusing.)

+    return false;
+  *path = FilePath(info.dli_fname);
+  return true;
+}
+
 }  // namespace
 
 namespace base {
 
 bool PathProviderMac(int key, FilePath* result) {
   switch (key) {
     case base::FILE_EXE:
-    case base::FILE_MODULE: {
       return GetNSExecutablePath(result);
-    }
+    case base::FILE_MODULE:
+      return GetModulePathForAddress(result,
+          reinterpret_cast<const void*>(&base::PathProviderMac));
     case base::DIR_CACHE:
       return base::mac::GetUserDirectory(NSCachesDirectory, result);
     case base::DIR_APP_DATA:
       return base::mac::GetUserDirectory(NSApplicationSupportDirectory, result);
     case base::DIR_SOURCE_ROOT: {
       // Go through PathService to catch overrides.
       if (!PathService::Get(base::FILE_EXE, result))
         return false;
 
       // Start with the executable's directory.
       *result = result->DirName();
       if (base::mac::AmIBundled()) {
         // The bundled app executables (Chromium, TestShell, etc) live five
         // levels down, eg:
         // src/xcodebuild/{Debug|Release}/Chromium.app/Contents/MacOS/Chromium
         *result = result->DirName().DirName().DirName().DirName().DirName();
       } else {
         // Unit tests execute two levels deep from the source root, eg:
         // src/xcodebuild/{Debug|Release}/base_unittests
         *result = result->DirName().DirName();
       }
       return true;
     }
     default:
       return false;
   }
 }
 
 }  // namespace base