Applies a number of optimizations that speed up defining a legacy element. These optimizations are mostly beneficial when a large number of elements are defined that are not used for initial render.
Fixes an issue with dedupingMixin that was causing info to be cached on the resulting class even when no mixin should be applied.
In Polymer.Class, avoids using LegacyElementMixin(HTMLElement) in favor of a cached LegacyElement.
Copies DisableUpgradeMixin into Polymer's legacy class generation. This avoids the need to mix this on top of all legacy elements.
Adds legacyNoAttributes setting which avoids setting observedAttributes and instead (1) applies the values of all attributes at create time, (2) patches set/removeAttribute so that they call attributeChangedCallback. This is faster since it avoids the work Polymer needs to do to calculate observedAttributes.
Applies a number of optimizations that speed up defining a legacy element. These optimizations are mostly beneficial when a large number of elements are defined that are not used for initial render.
dedupingMixinthat was causing info to be cached on the resulting class even when no mixin should be applied.LegacyElementMixin(HTMLElement)in favor of a cachedLegacyElement.DisableUpgradeMixininto Polymer's legacy class generation. This avoids the need to mix this on top of all legacy elements.legacyNoAttributessetting which avoids settingobservedAttributesand instead (1) applies the values of all attributes at create time, (2) patches set/removeAttribute so that they call attributeChangedCallback. This is faster since it avoids the work Polymer needs to do to calculateobservedAttributes.