Added support for isInherited flags to ComputedStyleBase

Added support for isInherited flags to ComputedStyleBase, and moved
visibilityIsInherited to ComputedStyleBase. This involved adding
additional code to generate the new inherited flag fields, as well as
adding a version of propagateIndependentInheritedProperties() to
ComputedStyleBase.

Visibility was already a generated field, but the inherited flag of its
generation was not yet being generated in ComputedStyleBase, so this
patch moves that field to be generated as well.

BUG=628043

Review-Url: https://codereview.chromium.org/2547403002
Cr-Commit-Position: refs/heads/master@{#436527}
5 files changed