Worker: Exclude source_code from GlobalScopeCreationParams for cleanup

For cleanup, this CL excludes |source_code| and |cached_meta_data| from
GlobalScopeCreationParams and passes them as separate arguments to functions.
This is because these fields are not used for creating a global scope but for
evaluating a worker script.

Also, this change simplifies worklets implementation and helps to implement
module worker because they don't need to pass |source_code| and
|cached_meta_data| from the main thread.

Bug: 680046, 710364
Change-Id: Icdf978ec136cb316c391a47e8306ba454e9b9876
Reviewed-on: https://chromium-review.googlesource.com/813454
Commit-Queue: Hiroki Nakagawa <nhiroki@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#522692}
21 files changed