Create task_manager namespace and wrap classes related to TaskManager with it.

chrome/browser/task_manager/os_resource_win.h

Index: chrome/browser/task_manager/os_resource_win.h
diff --git a/chrome/browser/task_manager/task_manager_os_resources_win.h b/chrome/browser/task_manager/os_resource_win.h
similarity index 72%
rename from chrome/browser/task_manager/task_manager_os_resources_win.h
rename to chrome/browser/task_manager/os_resource_win.h
index f0e7887bab318fefbb60297eaef116078d248f8e..f18000c3725ce075521f212c4dd388ea07d697e8 100644
--- a/chrome/browser/task_manager/task_manager_os_resources_win.h
+++ b/chrome/browser/task_manager/os_resource_win.h
@@ -2,11 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROME_BROWSER_TASK_MANAGER_TASK_MANAGER_OS_RESOURCES_WIN_H_
-#define CHROME_BROWSER_TASK_MANAGER_TASK_MANAGER_OS_RESOURCES_WIN_H_
+#ifndef CHROME_BROWSER_TASK_MANAGER_OS_RESOURCE_WIN_H_
+#define CHROME_BROWSER_TASK_MANAGER_OS_RESOURCE_WIN_H_
 
 #include "base/process_util.h"
 
+namespace task_manager {
+
 // Get the current number of GDI handles in use (and peak on >= Win7+).
 void GetWinGDIHandles(base::ProcessHandle process,
                       size_t* current,
@@ -17,4 +19,6 @@ void GetWinUSERHandles(base::ProcessHandle process,
                        size_t* current,
                        size_t* peak);
 
-#endif  // CHROME_BROWSER_TASK_MANAGER_TASK_MANAGER_OS_RESOURCES_WIN_H_
+}  // namespace task_manager
+
+#endif  // CHROME_BROWSER_TASK_MANAGER_OS_RESOURCE_WIN_H_