Remove DOMWebSocket::SubprotocolSeperator method

It is a static method which returns a constant ", " string, and which is
only used inside the implementation of DOMWebSocket. Replace it with a
compile-time constant.

Change-Id: I1bb9ab48421394e6b3f759536d53a56888a3af8f
Reviewed-on: https://chromium-review.googlesource.com/1151170Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
Commit-Queue: Adam Rice <ricea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#578519}

third_party/blink/renderer/modules/websockets/dom_websocket.cc

@@ -64,6 +64,7 @@
 
 static const size_t kMaxByteSizeForHistogram = 100 * 1000 * 1000;
 static const int32_t kBucketCountForMessageSizeHistogram = 50;
+static const char kWebSocketSubprotocolSeparator[] = ", ";
 
 namespace blink {
 
@@ -215,10 +216,6 @@ static void SetInvalidStateErrorForSendMethod(ExceptionState& exception_state) {
                                     "Still in CONNECTING state.");
 }
 
-const char* DOMWebSocket::SubprotocolSeperator() {
-  return ", ";
-}
-
 DOMWebSocket::DOMWebSocket(ExecutionContext* context)
     : PausableObject(context),
       state_(kConnecting),
@@ -375,7 +372,7 @@ void DOMWebSocket::Connect(const String& url,
 
   String protocol_string;
   if (!protocols.IsEmpty())
-    protocol_string = JoinStrings(protocols, SubprotocolSeperator());
+    protocol_string = JoinStrings(protocols, kWebSocketSubprotocolSeparator);
 
   origin_string_ = SecurityOrigin::Create(url_)->ToString();
   channel_ = CreateChannel(GetExecutionContext(), this);

third_party/blink/renderer/modules/websockets/dom_websocket.h

@@ -69,7 +69,6 @@ class MODULES_EXPORT DOMWebSocket : public EventTargetWithInlineData,
   USING_GARBAGE_COLLECTED_MIXIN(DOMWebSocket);
 
  public:
-  static const char* SubprotocolSeperator();
   // DOMWebSocket instances must be used with a wrapper since this class's
   // lifetime management is designed assuming the V8 holds a ref on it while
   // hasPendingActivity() returns true.