Remove dependency from GWT-JUnit on deRPC

GWT-JUnit never actually used deRPC, which additionally is being phased out
and its use now discouraged.

git fetch https://gwt.googlesource.com/gwt refs/changes/90/1290/2 && git cherry-pick FETCH_HEAD

Change-Id: I74c9d2e339187c2a47ccea4b0082c3a59ffe5ae4

Author: tbroyer

user/src/com/google/gwt/junit/server/JUnitHostImpl.java

@@ -15,6 +15,8 @@
  */
 package com.google.gwt.junit.server;
 
+import static com.google.gwt.user.client.rpc.RpcRequestBuilder.MODULE_BASE_HEADER;
+
 import com.google.gwt.core.server.impl.StackTraceDeobfuscator;
 import com.google.gwt.junit.JUnitFatalLaunchException;
 import com.google.gwt.junit.JUnitMessageQueue;
@@ -25,10 +27,12 @@
 import com.google.gwt.junit.client.impl.JUnitResult;
 import com.google.gwt.junit.linker.JUnitSymbolMapsLinker;
 import com.google.gwt.user.client.rpc.InvocationException;
-import com.google.gwt.user.server.rpc.HybridServiceServlet;
 import com.google.gwt.user.server.rpc.RPCServletUtils;
+import com.google.gwt.user.server.rpc.RemoteServiceServlet;
 
 import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
 import java.util.HashMap;
 import java.util.concurrent.atomic.AtomicInteger;
 
@@ -41,7 +45,7 @@
  * communication between the unit test code running in a browser and the real
  * test process.
  */
-public class JUnitHostImpl extends HybridServiceServlet implements JUnitHost {
+public class JUnitHostImpl extends RemoteServiceServlet implements JUnitHost {
 
   /**
    * A hook into GWTUnitTestShell, the underlying unit test process.
@@ -154,6 +158,31 @@ private String getClientDesc(HttpServletRequest request) {
     return machine + " / " + agent;
   }
 
+  /**
+   * Extract the module's base path from the current request.
+   * 
+   * @return the module's base path, modulo protocol and host, as reported by
+   *         {@link com.google.gwt.core.client.GWT#getModuleBaseURL()} or
+   *         <code>null</code> if the request did not contain the
+   *         {@value com.google.gwt.user.client.rpc.RpcRequestBuilder#MODULE_BASE_HEADER} header
+   */
+  private String getRequestModuleBasePath() {
+    try {
+      String header = getThreadLocalRequest().getHeader(MODULE_BASE_HEADER);
+      if (header == null) {
+        return null;
+      }
+      String path = new URL(header).getPath();
+      String contextPath = getThreadLocalRequest().getContextPath();
+      if (!path.startsWith(contextPath)) {
+        return null;
+      }
+      return path.substring(contextPath.length());
+    } catch (MalformedURLException e) {
+      return null;
+    }
+  }
+
   private void initResult(HttpServletRequest request, JUnitResult result) {
     result.setAgent(request.getHeader("User-Agent"));
     result.setHost(request.getRemoteHost());