[Extension Toolbar Redesign] Wants to act treatment, redux - left click
The bug fully describes the new behavior for an extension that wants to act
with the toolbar redesign turned on. This patch implements the new left-click
behavior, so that an otherwise-disabled extension action's clicks forward to
the context menu. That is, right clicking on a page action that wouldn't
previously be showing opens the menu, instead of running the action. (The user
can know when this will happen based on the extension action's enabled/disabled
state, which is indicated by greyscaling the action when disabled.)
BUG=417441
TBR=sky@chromium.org (media router action)
Review URL: https://codereview.chromium.org/
1216053013
Cr-Commit-Position: refs/heads/master@{#338067}