Worker: Rename WorkerReportingProxy::*WorkerScript to ClassicScript for cleanup

For consistency with ModuleScript, this CL renames...
- WillEvaluateWorkerScript to WillEvaluateClassicScript,
- DidEvaluateWorkerScript to DidEvaluateClassicScript, and
- WillEvaluateImportedScript to WillEvaluateImportedClassicScript.


Bug: 680046
Change-Id: I9120f1ed9d3923d901f32801d551a61bafba04ee
Reviewed-on: https://chromium-review.googlesource.com/967627
Commit-Queue: Hiroki Nakagawa <nhiroki@chromium.org>
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544049}
17 files changed