Merge "Adding DisplayBrightnessController.mLock detailed description" into main

    // The ID of the display tied to this DisplayBrightnessController

    private final int mDisplayId;

    // The lock which is to be used to synchronize the resources being used in this class

    // The lock which is to be used to synchronize the resources being used in this class.

    // mLock can be synchronized on while holding DisplayManagerService.mSyncRoot, so never call

    // methods that acquiring DisplayManagerService.mSyncRoot under mLock,

    // e.g. some BrightnessSetting methods.

    private final Object mLock = new Object();

    // The default screen brightness to be used when no value is available in BrightnessSetting.