Stop using WebCore namespace in generated code

Source/modules/BUILD.gn

Index: Source/modules/BUILD.gn
diff --git a/Source/modules/BUILD.gn b/Source/modules/BUILD.gn
index 0edaed65eabd729a7d9e996b0096312e91a6d251..d3a3c987aee1de9b237ad921a4c089b282aba916 100644
--- a/Source/modules/BUILD.gn
+++ b/Source/modules/BUILD.gn
@@ -58,7 +58,7 @@ make_file_arrays("modules_cache_polyfill") {
   resources = [
     "serviceworkers/polyfills/cachePolyfill.js",
   ]
-  namespace = "WebCore"
+  namespace = "blink"
 }
 
 # GYP version: WebKit/Source/modules/modules.gyp:modules (CacheStoragePolyfill action)
@@ -67,7 +67,7 @@ make_file_arrays("modules_cache_storage_polyfill") {
   resources = [
     "serviceworkers/polyfills/cacheStoragePolyfill.js",
   ]
-  namespace = "WebCore"
+  namespace = "blink"
 }
 
 # GYP version: WebKit/Source/modules/modules.gyp:modules_testing