Split options page code/html into its own set of files

tools/grit/grit/format/html_inline.py

Index: tools/grit/grit/format/html_inline.py
===================================================================
--- tools/grit/grit/format/html_inline.py	(revision 51178)
+++ tools/grit/grit/format/html_inline.py	(working copy)
@@ -107,6 +107,10 @@
       return src_match.group(0)
     return pattern % ReadFile(filepath)
 
+  def InlineIncludeFiles(src_match):
+    """Helper function to inline external script files"""
+    return InlineFileContents(src_match, '%s')
+
   def InlineScript(src_match):
     """Helper function to inline external script files"""
     return InlineFileContents(src_match, '<script>%s</script>')
@@ -152,6 +156,11 @@
       InlineCssFile,
       flat_text)
 
+  flat_text = re.sub(
+      '<!--\s*include\s+file="(?P<filename>[^"\']*)".*-->',
+      InlineIncludeFiles,
+      flat_text)
+
   # TODO(glen): Make this regex not match src="" text that is not inside a tag
   flat_text = re.sub('src="(?P<filename>[^"\']*)"',
                      SrcReplace,