Remove using directives ("using namespace x") from blink/renderer/build/.

Bug: 82078
Change-Id: Ida19b233a4b78d1fe5876c1689ebed57b09e0066
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1861634
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Auto-Submit: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#705860}

third_party/blink/renderer/build/scripts/templates/element_lookup_trie.cc.tmpl

@@ -11,12 +11,12 @@
 
 namespace blink {
 
-using namespace {{namespace|lower}}_names;
-
 const AtomicString& lookup{{namespace}}Tag(const UChar* data, unsigned length) {
   DCHECK(data);
   DCHECK(length);
-  {% macro trie_return_statement(tag) %}{{tag|symbol}}Tag.LocalName(){% endmacro %}
+  {% macro trie_return_statement(tag) -%}
+  {{namespace|lower}}_names::{{tag|symbol}}Tag.LocalName()
+  {%- endmacro %}
   {{ trie_length_switch(length_tries, trie_return_statement, false) | indent(4) }}
   return g_null_atom;
 }