Update Chrome's Active Setup version per component instead of as a single string.

chrome/installer/setup/install_worker.cc

Index: chrome/installer/setup/install_worker.cc
diff --git a/chrome/installer/setup/install_worker.cc b/chrome/installer/setup/install_worker.cc
index 4824016a21eafc096c1b9da61ad012fcbcf0dc18..e5d092a02be57cfadc8bc1e1b0a90bb66fa88444 100644
--- a/chrome/installer/setup/install_worker.cc
+++ b/chrome/installer/setup/install_worker.cc
@@ -20,6 +20,7 @@
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/path_service.h"
+#include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/version.h"
@@ -57,12 +58,6 @@ namespace installer {
 
 namespace {
 
-// The version identifying the work done by setup.exe --configure-user-settings
-// on user login by way of Active Setup.  Increase this value if the work done
-// in setup_main.cc's handling of kConfigureUserSettings changes and should be
-// executed again for all users.
-const wchar_t kActiveSetupVersion[] = L"43,0,0,0";
-
 // Although the UUID of the ChromeFrame class is used for the "current" value,
 // this is done only as a convenience; there is no need for the GUID of the Low
 // Rights policies to match the ChromeFrame class's GUID.  Hence, it is safe to
@@ -541,6 +536,32 @@ void CleanupBadCanaryDelegateExecuteRegistration(
   }
 }
 
+// Returns the version to be used for Active Setup as MM,XX,YY,ZZ where MM is
+// |kActiveSetupMajorVersion| and other components may be updated in various
+// situations. At this point YY represents the number of on-os-upgrade that were
+// handled by this installation and XX/ZZ are unused.
+base::string16 GetActiveSetupVersionFromExisting(
+    const base::string16& existing_version) {
+  // The major version and first component of the version identifying the work
+  // done by setup.exe --configure-user-settings on user login by way of Active
+  // Setup.  Increase this value if the work done in setup_main.cc's handling of
+  // kConfigureUserSettings changes and should be executed again for all users.
+  const base::char16 kActiveSetupMajorVersion[] = L"43";
+
+  std::vector<base::string16> version_components = base::SplitString(
+      existing_version, L",", base::TRIM_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
+
+  // If |existing_version| was empty or otherwise corrupted, turn it into a
+  // valid one.
+  if (version_components.size() != 4U)
+    version_components.assign(4U, L"0");
+
+  // Unconditionally update the major version.
+  version_components[0] = kActiveSetupMajorVersion;
+
+  return JoinString(version_components, L',');
+}
+
 }  // namespace
 
 // This method adds work items to create (or update) Chrome uninstall entry in
@@ -1241,7 +1262,7 @@ void AddInstallWorkItems(const InstallationState& original_state,
     AddDelegateExecuteWorkItems(installer_state, target_path, new_version,
                                 product, install_list);
 
-    AddActiveSetupWorkItems(installer_state, setup_path, new_version, product,
+    AddActiveSetupWorkItems(installer_state, new_version, product,
                             install_list);
   }
 
@@ -1399,7 +1420,6 @@ void AddDelegateExecuteWorkItems(const InstallerState& installer_state,
 }
 
 void AddActiveSetupWorkItems(const InstallerState& installer_state,
-                             const base::FilePath& setup_path,
                              const Version& new_version,
                              const Product& product,
                              WorkItemList* list) {
@@ -1462,8 +1482,7 @@ void AddActiveSetupWorkItems(const InstallerState& installer_state,
                                active_setup_path,
                                WorkItem::kWow64Default,
                                L"Version",
-                               kActiveSetupVersion,
-                               true);
+                               base::Bind(&GetActiveSetupVersionFromExisting));
 }
 
 void AddDeleteOldIELowRightsPolicyWorkItems(