[ChromeDriver] Update error code of ExecuteSetAlertText()

Make ExecuteSetAlertText() return kInvalidArgument according W3C standard

Bug: chromedriver:2003
Change-Id: Ibd65e8861f0a3f17bb21b54b0d031b88de7dc05c
Reviewed-on: https://chromium-review.googlesource.com/1226794
Reviewed-by: John Chen <johnchen@chromium.org>
Commit-Queue: Tatiana Buldina <buldina@chromium.org>
Cr-Commit-Position: refs/heads/master@{#591428}
2 files changed