Fixing guest processes to use the proper storage partition.

chrome/browser/profiles/profile_impl_io_data.cc

Index: chrome/browser/profiles/profile_impl_io_data.cc
diff --git a/chrome/browser/profiles/profile_impl_io_data.cc b/chrome/browser/profiles/profile_impl_io_data.cc
index 3920aecdebd54c683b05eb1184b83dcb7d11b040..384448711c65a537b5971e799a47ad37bbaf0433 100644
--- a/chrome/browser/profiles/profile_impl_io_data.cc
+++ b/chrome/browser/profiles/profile_impl_io_data.cc
@@ -9,6 +9,7 @@
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/stl_util.h"
+#include "base/string_util.h"
 #include "base/threading/worker_pool.h"
 #include "chrome/browser/api/prefs/pref_member.h"
 #include "chrome/browser/custom_handlers/protocol_handler_registry.h"
@@ -487,7 +488,7 @@ ProfileImplIOData::InitializeAppRequestContext(
         protocol_handler_interceptor) const {
   // If this is for a guest process, we should not persist cookies and http
   // cache.
-  bool is_guest_process = (app_id.find("guest-") != std::string::npos);
+  bool is_guest_process = StartsWithASCII(app_id, "guest-", true);
 
   // Copy most state from the main context.
   AppRequestContext* context = new AppRequestContext(load_time_stats());