Platform-specific prune state storage.

chrome/installer/setup/uninstall.cc

Index: chrome/installer/setup/uninstall.cc
diff --git a/chrome/installer/setup/uninstall.cc b/chrome/installer/setup/uninstall.cc
index 0404b79140a31ff838dfdf374e4a916f057f4b6b..1fba48d91c7c6c99e68e7f49777e48bcfa6a1c1c 100644
--- a/chrome/installer/setup/uninstall.cc
+++ b/chrome/installer/setup/uninstall.cc
@@ -837,7 +837,7 @@ void UninstallActiveSetupEntries(const InstallerState& installer_state,
 }
 
 // Removes the persistent blacklist state for the current user.  Note: this will
-// not remove the state for users other than the one uninstalling chrome on a
+// not remove the state for users other than the one uninstalling Chrome on a
 // system-level install (http://crbug.com/388725). Doing so would require
 // extracting the per-user registry hive iteration from
 // UninstallActiveSetupEntries so that it could service multiple tasks.
@@ -850,6 +850,15 @@ void RemoveBlacklistState() {
                                  0);  // wow64_access
 }
 
+// Removes the persistent state for |distribution| for the current user. Note:
+// this will not remove the state for users other than the one uninstalling
+// Chrome on a system-level install; see RemoveBlacklistState for details.

[robertshield, 2015/09/01 14:20:12]

This deletes all persistent state, more than just what is saved in this CL. 

This is almost certainly right, but I see a bunch of stuff stored under that
key, did you double check that none of it is meant to survive an
uninstall-reinstall cycle?

[grt (UTC plus 2), 2015/09/03 18:12:06]

No, I didn't. As a policy, I believe that selecting "Also delete your browsing
data?" on uninstall should remove all traces of Chrome. Unfortunately, this key
is used as a public configuration knob for certain features so blindly removing
it like this won't work. I'll address this in a separate CL.

+void RemoveDistributionRegistryState(BrowserDistribution* distribution) {
+  base::string16 key_name(L"Software\\");
+  key_name += distribution->GetInstallSubDir();
+  InstallUtil::DeleteRegistryKey(HKEY_CURRENT_USER, key_name, KEY_WOW64_32KEY);
+}
+
 }  // namespace
 
 DeleteResult DeleteChromeDirectoriesIfEmpty(
@@ -1339,8 +1348,10 @@ InstallStatus UninstallProduct(const InstallationState& original_state,
     }
   }
 
-  if (delete_profile)
+  if (delete_profile) {
     DeleteUserDataDir(user_data_dir, product.is_chrome_frame());
+    RemoveDistributionRegistryState(browser_dist);
+  }
 
   if (!force_uninstall) {
     VLOG(1) << "Uninstallation complete. Launching post-uninstall operations.";