* perf: make ElectronUsbDelegate::controller_map_ an absl::flat_hash_map
* perf: make ElectronSerialDelegate::controller_map_ an absl::flat_hash_map
* perf: make ElectronHidDelegate::controller_map_ an absl::flat_hash_map
* perf: make FrameTreeNodeIdMap an absl::flat_hash_map
* perf: make AutofillDriverFactory::driver_map_ an absl::flat_hash_map
* perf: make asar::Archive::external_files_ an absl::flat_hash_map
* perf: make VersionIdMap an absl::flat_hash_map
* perf: make ObjectCache::proxy_map_ an absl::flat_hash_map
* docs: add TODO to investigate absl map in KeyWeakMap
- Prefer GURL() when we want to return a non-reference empty URL.
- In ServiceWorkerMain::GetStorageKey(), use a reference instead
of instantiating a new temporary GURL.
From url/gurl.h:
> // Returns a reference to a singleton empty GURL. This object is for
> // callers who return references but don't have anything to return in
> // some cases. If you just want an empty URL for normal use, prefer
> // GURL().
* feat: ServiceWorkerMain
* refactor: disconnect remote
* handle version_info_ nullptr case
* initiate finish request when possible and enumerate errors
* explicit name for test method
* oops
* fix: wait for redundant version to stop before destroying
* docs: clarify when undefined is returned
* chore: remove extra semicolons
