Factor and simplify generation of the lookup trie used for HTMLLookupTrie.

third_party/WebKit/Source/build/scripts/templates/macros.tmpl

 {#
     FIXME: Do we need to put license blocks in generated files?
 #}
 {% macro license() %}
 // Copyright (c) 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 {%- endmacro %}
+
+
+{% macro trie_leaf(index, object, return_macro, lowercase_data) %}
+{% set name, value = object.items()[0] %}
+{% if name|length %}
+if (
+    {%- for c in name -%}
+        {%- if lowercase_data -%}
+    {{ " && " if not loop.first }}toASCIILower(data[{{index + loop.index0}}]) == '{{c}}'
+        {%- else -%}
+    {{ " && " if not loop.first }}data[{{index + loop.index0}}] == '{{c}}'
+        {%- endif -%}
+        {%- endfor -%}
+    )
+    return {{ return_macro(value) }};
+break;
+{% else %}
+return {{ return_macro(value) }};
+{% endif %}
+{% endmacro %}
+
+
+{% macro trie_switch(trie, index, return_macro, lowercase_data) %}
+{% if trie|length == 1 and trie.values()[0] is string %}
+{{ trie_leaf(index, trie, return_macro, lowercase_data) -}}
+{% else %}
+    {% if lowercase_data %}
+switch (toASCIILower(data[{{index}}])) {
+    {% else %}
+switch (data[{{index}}]) {
+    {% endif %}
+    {% for char, value in trie.items()|sort %}
+case '{{char}}':
+    {{ trie_switch(value, index + 1, return_macro, lowercase_data) | indent(4) }}
+    {% endfor %}
+}
+break;
+{% endif %}
+{% endmacro %}
+
+
+{% macro trie_length_switch(length_tries, return_macro, lowercase_data) %}
+switch (length) {
+{% for length, trie in length_tries %}
+case {{ length }}:
+    {{ trie_switch(trie, 0, return_macro, lowercase_data) | indent(4) }}
+{% endfor %}
+}
+{% endmacro %}