Merge 134917 - Web Inspector: [Overrides] Device metrics get reset on navigation, yet remain in the…

Merge 134917 - Web Inspector: [Overrides] Device metrics get reset on navigation, yet remain in the Overrides view
https://bugs.webkit.org/show_bug.cgi?id=102467

Reviewed by Pavel Feldman.

Restore the device metrics overrides from the inspector cookie in InspectorPageAgent::restore().
Drive-by: move the script execution and FPS counter display state restoration from enable() into restore(),
so that they will get restored only upon page navigation, not upon any agent enablement.

* inspector/InspectorPageAgent.cpp:
(WebCore::InspectorPageAgent::restore): Restore device metrics overrides, script execution and FPS counter display state.
(WebCore::InspectorPageAgent::enable): Don't restore script execution and FPS counter display state on any enablement.

TBR=apavlov@chromium.org
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=135250