Add comment explaining fix and added explicit HistoryService dependency in predictor.

chrome/browser/printing/cloud_print/test/cloud_print_policy_browsertest.cc

Index: chrome/browser/printing/cloud_print/test/cloud_print_policy_browsertest.cc
diff --git a/chrome/browser/printing/cloud_print/test/cloud_print_policy_browsertest.cc b/chrome/browser/printing/cloud_print/test/cloud_print_policy_browsertest.cc
index c7151794823e760ebc9a774eb7cd6dc6f910822f..50034ccc4781118d4aafcc4a20c79764a5db043f 100644
--- a/chrome/browser/printing/cloud_print/test/cloud_print_policy_browsertest.cc
+++ b/chrome/browser/printing/cloud_print/test/cloud_print_policy_browsertest.cc
@@ -58,6 +58,10 @@ IN_PROC_BROWSER_TEST_F(CloudPrintPolicyTest, NormalPassedFlag) {
 IN_PROC_BROWSER_TEST_F(CloudPrintPolicyTest, CloudPrintPolicyFlag) {
   CommandLine new_command_line(GetCommandLineForRelaunch());
   new_command_line.AppendSwitch(switches::kCheckCloudPrintConnectorPolicy);
+  // This is important for the test as the way the browser process is launched
+  // here causes the predictor databases to be initialized multiple times. This
+  // is not an issue for production where the process is launched as a service
+  // and a Profile is not created. See http://crbug.com/140466 for more details.
   new_command_line.AppendSwitchASCII(
       switches::kSpeculativeResourcePrefetching,
       switches::kSpeculativeResourcePrefetchingDisabled);