Use Chrome for karma debugging (#4007)

Author: schmidt-sebastian

packages/firestore/package.json

@@ -28,13 +28,13 @@
     "test:lite": "node ./scripts/run-tests.js --emulator --platform node_lite --main=lite/index.ts 'lite/test/**/*.test.ts'",
     "test:lite:prod": "node ./scripts/run-tests.js --platform node_lite --main=lite/index.ts 'lite/test/**/*.test.ts'",
     "test:lite:browser": "karma start --single-run --lite",
-    "test:lite:browser:debug": "karma start --single-run --lite --auto-watch",
+    "test:lite:browser:debug": "karma start --browsers=Chrome --lite --auto-watch",
     "test:exp": "node ./scripts/run-tests.js --emulator --main=exp/index.ts test/integration/api/*.test.ts",
     "test:exp:prod": "node ./scripts/run-tests.js --main=exp/index.ts test/integration/api/*.test.ts",
     "test:exp:persistence": "node ./scripts/run-tests.js --emulator --persistence --main=exp/index.ts test/integration/api/*.test.ts",
     "test:exp:persistence:prod": "node ./scripts/run-tests.js --persistence --main=exp/index.ts test/integration/api/*.test.ts",
     "test:exp:browser": "karma start --single-run --exp",
-    "test:exp:browser:debug": "karma start --single-run --exp --auto-watch",
+    "test:exp:browser:debug": "karma start --browsers=Chrome --exp --auto-watch",
     "test": "run-s lint test:all",
     "test:ci": "node ../../scripts/run_tests_in_ci.js -s test:all",
     "test:all": "run-p test:browser test:lite:browser test:exp:browser test:travis test:minified",