Use TypeScript-authored files in coverage/

R=aerotwist@chromium.org

Bug: 1011811
Change-Id: Ibb4345721cd288095343d0ae3215db63bc420867
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2550693
Auto-Submit: Tim van der Lippe <tvanderlippe@chromium.org>
Reviewed-by: Jack Franklin <jacktfranklin@chromium.org>
Commit-Queue: Tim van der Lippe <tvanderlippe@chromium.org>

front_end/coverage/BUILD.gn

@@ -31,7 +31,7 @@ devtools_module("coverage") {
 }
 
 devtools_entrypoint("bundle") {
-  entrypoint = "coverage.js"
+  entrypoint = "coverage.ts"
 
   deps = [ ":coverage" ]
 }

front_end/coverage/module.json

@@ -58,12 +58,10 @@
     "workspace"
   ],
   "modules": [
-    "coverage.js",
-    "coverage-legacy.js",
-    "CoverageModel.js",
-    "CoverageListView.js",
-    "CoverageView.js",
-    "CoverageDecorationManager.js"
+    "coverage-legacy.js"
+  ],
+  "skip_compilation": [
+    "coverage-legacy.js"
   ],
   "resources": [
     "coverageListView.css",