Avoid WTF::Vector::at() and operator[] in core/html.

third_party/WebKit/Source/core/html/MediaFragmentURIParser.cpp

Index: third_party/WebKit/Source/core/html/MediaFragmentURIParser.cpp
diff --git a/third_party/WebKit/Source/core/html/MediaFragmentURIParser.cpp b/third_party/WebKit/Source/core/html/MediaFragmentURIParser.cpp
index 3630fc508e83aa2fdb49bede2fba214a56d57cd7..3db9fae10dec36247579443a7ce76a21e1d918ff 100644
--- a/third_party/WebKit/Source/core/html/MediaFragmentURIParser.cpp
+++ b/third_party/WebKit/Source/core/html/MediaFragmentURIParser.cpp
@@ -150,9 +150,7 @@ void MediaFragmentURIParser::parseTimeFragment() {
 
   m_timeFormat = Invalid;
 
-  for (unsigned i = 0; i < m_fragments.size(); ++i) {
-    std::pair<String, String>& fragment = m_fragments[i];
-
+  for (const auto& fragment : m_fragments) {
     DCHECK(fragment.first.is8Bit());
     DCHECK(fragment.second.is8Bit());