Move implementation of QuotaManager.getVolumeInfo to base::SysInfo.

base/sys_info.h

Index: base/sys_info.h
diff --git a/base/sys_info.h b/base/sys_info.h
index 5686dcbb49d22f8dc32cc73301932cb9eb3712ea..caef701e4714ec9ace4f2355f7887f182475f8e3 100644
--- a/base/sys_info.h
+++ b/base/sys_info.h
@@ -50,6 +50,12 @@ class BASE_EXPORT SysInfo {
   // or -1 on failure.
   static int64_t AmountOfFreeDiskSpace(const FilePath& path);
 
+  // Gets the total disk space and available disk space in bytes on the volume
+  // containing |path|, and returns true on success.
+  static bool GetDiskSpaceInfo(const FilePath& path,
+                               int64_t* available_bytes,
+                               int64_t* total_bytes);
+
   // Returns system uptime.
   static TimeDelta Uptime();