Optimize some startup code related to about:flags handling.
Previously, the code would create a set from all the known
flags and compare the specified flags against them.
But actually this is less efficient than just the O(n*m) search,
because n being the number of flags set by the user and m being
the number of available flags, since n will likely be small or 0
and then we don't need to do a lot of work. In particular, this
also avoids copying a bunch of strings.
Bug: 904575
Change-Id: I63e59d439c432338aea71eb6258e8f8b42f04921
Reviewed-on: https://chromium-review.googlesource.com/c/1334413
Commit-Queue: Alexei Svitkine <[email protected]>
Reviewed-by: ssid <[email protected]>
Cr-Commit-Position: refs/heads/master@{#608128}diff --git a/components/flags_ui/flags_state.h b/components/flags_ui/flags_state.h
index 21ad59df5..6ce8321 100644
--- a/components/flags_ui/flags_state.h
+++ b/components/flags_ui/flags_state.h
@@ -176,10 +176,15 @@
bool feature_state,
base::CommandLine* command_line);
- // Removes all entries from prefs::kEnabledLabsExperiments that are unknown,
- // to prevent this list to become very long as entries are added and removed.
- void SanitizeList(FlagsStorage* flags_storage) const;
+ // Sanitizes |enabled_entries| to only contain entries that are defined in the
+ // |feature_entries_| and whose |supported_platforms| matches |platform_mask|.
+ // Pass -1 to |platform_mask| to not do platform filtering.
+ std::set<std::string> SanitizeList(
+ const std::set<std::string>& enabled_entries,
+ int platform_mask) const;
+ // Gets sanitized entries from |flags_storage|, filtering out any entries that
+ // don't exist in |feature_entries_|, and updates |flags_storage|.
void GetSanitizedEnabledFlags(FlagsStorage* flags_storage,
std::set<std::string>* result) const;
