Add backend support for collecting the time it takes to
install each Flow.

The new REST call is "wm/flow/measurement-get-per-flow-install-time/json"
The result is returned in a multi-line string with the following format
per line:

  ThreadAndTimePerFlow <ThreadId> <TotalThreads> <Time(ns)>
diff --git a/src/main/java/net/floodlightcontroller/flowcache/web/MeasurementGetPerFlowInstallTimeFlowResource.java b/src/main/java/net/floodlightcontroller/flowcache/web/MeasurementGetPerFlowInstallTimeFlowResource.java
new file mode 100644
index 0000000..adaecc8
--- /dev/null
+++ b/src/main/java/net/floodlightcontroller/flowcache/web/MeasurementGetPerFlowInstallTimeFlowResource.java
@@ -0,0 +1,37 @@
+package net.floodlightcontroller.flowcache.web;
+
+import net.floodlightcontroller.flowcache.IFlowService;
+import net.floodlightcontroller.util.FlowId;
+
+import org.openflow.util.HexString;
+import org.restlet.resource.Get;
+import org.restlet.resource.ServerResource;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class MeasurementGetPerFlowInstallTimeFlowResource extends ServerResource {
+    protected static Logger log = LoggerFactory.getLogger(MeasurementGetPerFlowInstallTimeFlowResource.class);
+
+    @Get("json")
+    public String retrieve() {
+	String result = null;
+
+        IFlowService flowService =
+                (IFlowService)getContext().getAttributes().
+                get(IFlowService.class.getCanonicalName());
+
+        if (flowService == null) {
+	    log.debug("ONOS Flow Service not found");
+	    return result;
+	}
+
+	// Extract the arguments
+
+	// Process the request
+	result = flowService.measurementGetPerFlowInstallTime();
+
+	log.debug("Measurement Get Install Paths Time (nsec): " + result);
+
+	return result;
+    }
+}