Added comments to setlocale call.

base/test/test_suite.cc

 // Copyright (c) 2011 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/test/test_suite.h"
 
 #include "base/at_exit.h"
 #include "base/base_paths.h"
 #include "base/base_switches.h"
 #include "base/command_line.h"
@@ skipping 61 matching lines @@
 const char TestSuite::kStrictFailureHandling[] = "strict_failure_handling";
 
 TestSuite::TestSuite(int argc, char** argv) {
 #if defined(OS_WIN)
   testing::GTEST_FLAG(catch_exceptions) = false;
 #endif
   base::EnableTerminationOnHeapCorruption();
   CommandLine::Init(argc, argv);
   testing::InitGoogleTest(&argc, argv);
 #if defined(OS_LINUX) && defined(USE_AURA)
+  // When calling native char conversion functions (e.g wrctomb) we need to
+  // have the locale set. In the absence of such a call the "C" locale is the
+  // default. In the gtk code (below) gtk_init() implicitly sets a locale.
   setlocale(LC_ALL, "");
 #elif defined(TOOLKIT_USES_GTK)
   gtk_init_check(&argc, &argv);
 #endif  // defined(TOOLKIT_USES_GTK)
   // Don't add additional code to this constructor.  Instead add it to
   // Initialize().  See bug 6436.
 }
 
 TestSuite::~TestSuite() {
   CommandLine::Reset();
@@ skipping 165 matching lines @@
 #endif
 
   CatchMaybeTests();
   ResetCommandLine();
 
   TestTimeouts::Initialize();
 }
 
 void TestSuite::Shutdown() {
 }