Do not show translate bar for MHTML files.

url/url_parse.cc

Index: url/url_parse.cc
diff --git a/url/url_parse.cc b/url/url_parse.cc
index 0d9c6dd1c9950cee13a8a1a4365bb59a9203a472..fb3c988930bef1bc968770291d0334739fceb51c 100644
--- a/url/url_parse.cc
+++ b/url/url_parse.cc
@@ -645,6 +645,44 @@ void DoExtractFileName(const CHAR* spec,
 }
 
 template<typename CHAR>
+void DoExtractFileExtension(const CHAR* spec,
+                            const Component& path,
+                            Component* file_extension) {
+
+  Component file_name;
+  DoExtractFileName(spec, path, &file_name);
+
+  // If there's no file specified in the path, there's no file extension
+  if (!file_name.is_valid()) {
+    file_extension->reset();
+    return;
+  }
+
+  // Search backwards for file delimiter '.'
+  // We don't check the first character, because if the file name starts with
+  // a '.' the rest of the file name is not typically considered a file
+  // extension.
+  int file_delimiter = -1;
+  for (int i = file_name.end() - 1; i > file_name.begin; i--) {
+    if (spec[i] == '.') {
+      file_delimiter = i;
+      break;
+    }
+  }
+
+  // If we didn't find a file delimiter, there is no file extension
+  if (file_delimiter == -1) {
+    file_extension->reset();
+    return;
+  }
+
+  // Return everything in the filename following the delimiter
+  *file_extension = MakeRange(file_delimiter+1, file_name.end());
+  return;
+
+}
+
+template<typename CHAR>
 bool DoExtractQueryKeyValue(const CHAR* spec,
                             Component* query,
                             Component* key,
@@ -818,6 +856,18 @@ void ExtractFileName(const base::char16* url,
   DoExtractFileName(url, path, file_name);
 }
 
+void ExtractFileExtension(const char* url,
+                          const Component& path,
+                          Component* file_extension) {
+  DoExtractFileExtension(url, path, file_extension);
+}
+
+void ExtractFileExtension(const base::char16* url,
+                          const Component& path,
+                          Component* file_extension) {
+  DoExtractFileExtension(url, path, file_extension);
+}
+
 bool ExtractQueryKeyValue(const char* url,
                           Component* query,
                           Component* key,