MacViews: Enable acceptsFirstMouse for BridgedContentView.
MacViews: Enable acceptsFirstMouse for BridgedContentView.

This allows an initial mouse click on an inactive window to be accepted
immediately, so two clicks are not required (i.e. one to activate the view and
the second to send the mouse event to the view itself).

See linked bugs for certificate viewer and tab dragging, both which require
this to be enabled.

BUG=594079,587239

Review URL: https://codereview.chromium.org/1815563002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#382240}

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