Avoid separate function for `InspectorFrontendHost.clearFileSystem`
Avoid separate function for `InspectorFrontendHost.clearFileSystem`

Move `clearFileSytem()` functionality into the `removeFileSystem()`
method. https://crrev.com/c/3620364 which initially added this method
caused console errors because `initializeInspectorFrontendHost()`
iterates over all properties.

Bug: 1313436
Change-Id: I3244f8c976daaf093e95d94e9ddb1074a1f08d5c
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/3641411
Reviewed-by: Danil Somsikov <f16a5ee11618cab93684e694f9aa762d34f02920@chromium.org>
Commit-Queue: Wolfgang Beyer <573aa99bb19da47d816981118f95c945310dd3f4@chromium.org>

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