Always suffix ChromeHTML entries on Windows for user-level installs.

chrome/installer/util/install_util.cc

Index: chrome/installer/util/install_util.cc
diff --git a/chrome/installer/util/install_util.cc b/chrome/installer/util/install_util.cc
index 5f4e2386282c85d44c43f4c0940a950a4e99d4b7..63bba526b72f35532185190f3279bac0594969ac 100644
--- a/chrome/installer/util/install_util.cc
+++ b/chrome/installer/util/install_util.cc
@@ -360,8 +360,8 @@ bool InstallUtil::HasDelegateExecuteHandler(BrowserDistribution* dist,
 }
 
 // This method tries to delete a registry key and logs an error message
-// in case of failure. It returns true if deletion is successful,
-// otherwise false.
+// in case of failure. It returns true if deletion is successful (or the key did
+// not exist), otherwise false.
 bool InstallUtil::DeleteRegistryKey(HKEY root_key,
                                     const std::wstring& key_path) {
   VLOG(1) << "Deleting registry key " << key_path;
@@ -375,11 +375,18 @@ bool InstallUtil::DeleteRegistryKey(HKEY root_key,
 }
 
 // This method tries to delete a registry value and logs an error message
-// in case of failure. It returns true if deletion is successful,
-// otherwise false.
+// in case of failure. It returns true if deletion is successful (or the key did
+// not exist), otherwise false.
 bool InstallUtil::DeleteRegistryValue(HKEY reg_root,
                                       const std::wstring& key_path,
                                       const std::wstring& value_name) {
+  // Return true immediately if the key doesn't exist (otherwise, creating a key
+  // with KEY_ALL_ACCESS in the next step creates the key and all its parents if
+  // they don't exist, in which case new parents are left behind post-deletion).
+  RegKey key_read_only(reg_root, key_path.c_str(), KEY_QUERY_VALUE);
+  if (!key_read_only.Valid())
+    return true;
+
   RegKey key(reg_root, key_path.c_str(), KEY_ALL_ACCESS);

[gab, 2012/05/30 20:08:39]

This step was causing RemoveBadWindows8RegistrationIfNeeded() to leave
HKEY_CURRENT_USER\Software\Classes\ChromeHTML behind after deleting
HKEY_CURRENT_USER\Software\Classes\ChromeHTML\shell\open\command\DelegateExecute.

The new code above fixes it.

[grt (UTC plus 2), 2012/05/30 20:37:40]

Please use something along the lines of:

RegKey key;
LONG result = key.Open(reg_root, key_path.c_str(), KEY_SET_VALUE);
if (result == ERROR_SUCCESS)
  result = key.DeleteValue(value_name.c_str());
if (result != ERROR_SUCCESS && result != ERROR_FILE_NOT_FOUND) {
  LOG(ERROR) << yadda yadda;
  return false;
}
return true;

[gab, 2012/06/01 00:16:01]

Done.

   VLOG(1) << "Deleting registry value " << value_name;
   if (key.HasValue(value_name.c_str())) {