Merge pull request #12 from quamotion/fixes/optional-arguments

...eDevTools/Protocol/Chrome/Page/ScreencastFrameMetadata.cs

.../Protocol/Chrome/Page/ScreencastVisibilityChangedEvent.cs

...eDevTools/Protocol/Chrome/Page/SearchInResourceCommand.cs

...s/Protocol/Chrome/Page/SetDeviceMetricsOverrideCommand.cs

...ols/Protocol/Chrome/Page/SetGeolocationOverrideCommand.cs

...DevTools/Protocol/Chrome/Page/SetOverlayMessageCommand.cs

...rotocol/Chrome/Page/SetShowViewportSizeOnResizeCommand.cs

...s/Protocol/Chrome/Page/SetTouchEmulationEnabledCommand.cs

...meDevTools/Protocol/Chrome/Page/StartScreencastCommand.cs

...hromeDevTools/Protocol/Chrome/Power/DataAvailableEvent.cs

source/ChromeDevTools/Protocol/Chrome/Profiler/CPUProfile.cs

...s/Protocol/Chrome/Profiler/ConsoleProfileFinishedEvent.cs

...ls/Protocol/Chrome/Profiler/ConsoleProfileStartedEvent.cs

...ce/ChromeDevTools/Protocol/Chrome/Runtime/CallArgument.cs

...DevTools/Protocol/Chrome/Runtime/CallFunctionOnCommand.cs

.../Protocol/Chrome/Runtime/CallFunctionOnCommandResponse.cs

...e/ChromeDevTools/Protocol/Chrome/Runtime/CustomPreview.cs

...ce/ChromeDevTools/Protocol/Chrome/Runtime/EntryPreview.cs

...ChromeDevTools/Protocol/Chrome/Runtime/EvaluateCommand.cs

...vTools/Protocol/Chrome/Runtime/EvaluateCommandResponse.cs