Improve EnterpriseInstallAttributes::ReadCacheFile() doc.

chrome/browser/chromeos/policy/enterprise_install_attributes.h

Index: chrome/browser/chromeos/policy/enterprise_install_attributes.h
diff --git a/chrome/browser/chromeos/policy/enterprise_install_attributes.h b/chrome/browser/chromeos/policy/enterprise_install_attributes.h
index 83f95ccde803b7848d084fd00e2878840aeb4ffb..f3ec5e0b5aef5a9b54ce8ff9410aae0a8a665403 100644
--- a/chrome/browser/chromeos/policy/enterprise_install_attributes.h
+++ b/chrome/browser/chromeos/policy/enterprise_install_attributes.h
@@ -54,9 +54,10 @@ class EnterpriseInstallAttributes {
       chromeos::CryptohomeClient* cryptohome_client);
   ~EnterpriseInstallAttributes();
 
-  // Reads data from the cache file. The cache file is used to work around slow
-  // cryptohome startup, which takes a while to register its DBus interface.
-  // See http://crosbug.com/37367 for background on this.
+  // Reads data from the cache file which is created early during the boot
+  // process.  The cache file is used to work around slow cryptohome startup,
+  // which takes a while to register its DBus interface.  See
+  // http://crosbug.com/37367 for background on this.
   void ReadCacheFile(const base::FilePath& cache_file);
 
   // Makes sure the local caches for enterprise-related install attributes are