base: Remove the string logging from CHECK().

extensions/shell/browser/shell_extension_system.cc

Index: extensions/shell/browser/shell_extension_system.cc
diff --git a/extensions/shell/browser/shell_extension_system.cc b/extensions/shell/browser/shell_extension_system.cc
index df9c433e6ecbc8c809b2f3f3e261adc7a800c2ba..f615e318ea94b93569110464f17919984289a531 100644
--- a/extensions/shell/browser/shell_extension_system.cc
+++ b/extensions/shell/browser/shell_extension_system.cc
@@ -45,7 +45,7 @@ const Extension* ShellExtensionSystem::LoadApp(const base::FilePath& app_dir) {
   // app_shell only supports unpacked extensions.
   // NOTE: If you add packed extension support consider removing the flag
   // FOLLOW_SYMLINKS_ANYWHERE below. Packed extensions should not have symlinks.
-  CHECK(base::DirectoryExists(app_dir)) << app_dir.AsUTF8Unsafe();
+  CHECK(base::DirectoryExists(app_dir));
   int load_flags = Extension::FOLLOW_SYMLINKS_ANYWHERE;
   std::string load_error;
   scoped_refptr<Extension> extension = file_util::LoadExtension(