Encode the Last-Event-ID header in EventSource as UTF-8.

HTTP headers are byte strings, so anything outside of
ASCII needs to be explicitly encoded one way or another.

BUG=429569

Review URL: https://codereview.chromium.org/836823002

git-svn-id: svn://svn.chromium.org/blink/trunk@201248 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/LayoutTests/http/tests/eventsource/eventsource-reconnect-expected.txt

@@ -5,11 +5,11 @@ On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE
 
 PASS es.readyState is es.CONNECTING
 PASS es.readyState is es.OPEN
-PASS evt.lastEventId is "77"
+PASS evt.lastEventId is "77☃"
 PASS es.readyState is es.CONNECTING
 PASS es.readyState is es.OPEN
-PASS evt.data is "77"
-PASS evt.lastEventId is "77"
+PASS evt.data is "77☃"
+PASS evt.lastEventId is "77☃"
 PASS es.readyState is es.CLOSED
 PASS successfullyParsed is true
 

third_party/WebKit/LayoutTests/http/tests/eventsource/resources/reconnect.php

@@ -5,7 +5,8 @@ $lastEventId = $_SERVER['HTTP_LAST_EVENT_ID'];
 if ($lastEventId)
     echo "data: $lastEventId\n\n";
 else {
-    echo "id: 77\n";
+    # Include a non-ASCII character to test the client encodes it correctly.
+    echo "id: 77☃\n";
     echo "retry: 300\n";
     echo "data: hello\n\n";
     echo "data: discarded";

third_party/WebKit/LayoutTests/http/tests/eventsource/script-tests/eventsource-reconnect.js

@@ -24,8 +24,8 @@ var evt;
 es.onmessage = function (arg) {
     evt = arg;
     if (errCount)
-        shouldBeEqualToString("evt.data", "77");
-    shouldBeEqualToString("evt.lastEventId", "77");
+        shouldBeEqualToString("evt.data", "77\u2603");
+    shouldBeEqualToString("evt.lastEventId", "77\u2603");
 };
 
 es.onerror = function () {

third_party/WebKit/LayoutTests/http/tests/eventsource/workers/eventsource-reconnect-expected.txt

@@ -6,11 +6,11 @@ On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE
 Starting worker: ../script-tests/eventsource-reconnect.js
 PASS [Worker] es.readyState is es.CONNECTING
 PASS [Worker] es.readyState is es.OPEN
-PASS [Worker] evt.lastEventId is "77"
+PASS [Worker] evt.lastEventId is "77☃"
 PASS [Worker] es.readyState is es.CONNECTING
 PASS [Worker] es.readyState is es.OPEN
-PASS [Worker] evt.data is "77"
-PASS [Worker] evt.lastEventId is "77"
+PASS [Worker] evt.data is "77☃"
+PASS [Worker] evt.lastEventId is "77☃"
 PASS [Worker] es.readyState is es.CLOSED
 PASS successfullyParsed is true
 

third_party/WebKit/Source/core/page/EventSource.cpp

@@ -127,8 +127,12 @@ void EventSource::connect()
     request.setHTTPHeaderField("Accept", "text/event-stream");
     request.setHTTPHeaderField("Cache-Control", "no-cache");
     request.setRequestContext(WebURLRequest::RequestContextEventSource);
-    if (!m_lastEventId.isEmpty())
-        request.setHTTPHeaderField("Last-Event-ID", m_lastEventId);
+    if (!m_lastEventId.isEmpty()) {
+        // HTTP headers are Latin-1 byte strings, but the Last-Event-ID header is encoded as UTF-8.
+        // TODO(davidben): This should be captured in the type of setHTTPHeaderField's arguments.
+        CString lastEventIdUtf8 = m_lastEventId.utf8();
+        request.setHTTPHeaderField("Last-Event-ID", AtomicString(reinterpret_cast<const LChar*>(lastEventIdUtf8.data()), lastEventIdUtf8.length()));
+    }
 
     SecurityOrigin* origin = executionContext.securityOrigin();