Add filtering by priority in the Network filter area.

third_party/WebKit/Source/devtools/front_end/components/NetworkConditionsSelector.js

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 /**
  * @unrestricted
  */
 Components.NetworkConditionsSelector = class {
   /**
    * @param {function(!Array<!Components.NetworkConditionsGroup>):!Array<?SDK.NetworkManager.Conditions>} populateCallback
    * @param {function(number)} selectCallback
@@ skipping 466 matching lines @@
     }
     if (actionId === 'components.network-offline') {
       SDK.multitargetNetworkManager.setNetworkConditions(SDK.NetworkManager.OfflineConditions);
       return true;
     }
     return false;
   }
 };
 
 /**
- * @param {?Protocol.Network.ResourcePriority} priority
+ * @param {!Protocol.Network.ResourcePriority} priority
  * @return {string}
  */
 Components.uiLabelForPriority = function(priority) {
-  var labelMap = Components.uiLabelForPriority._priorityToUILabel;
-  if (!labelMap) {
-    labelMap = new Map([
-      [Protocol.Network.ResourcePriority.VeryLow, Common.UIString('Lowest')],
-      [Protocol.Network.ResourcePriority.Low, Common.UIString('Low')],
-      [Protocol.Network.ResourcePriority.Medium, Common.UIString('Medium')],
-      [Protocol.Network.ResourcePriority.High, Common.UIString('High')],
-      [Protocol.Network.ResourcePriority.VeryHigh, Common.UIString('Highest')]
-    ]);
-    Components.uiLabelForPriority._priorityToUILabel = labelMap;
-  }
-  return labelMap.get(priority) || Common.UIString('Unknown');
+  var map = Components.priorityUiLabelMap();
+  return map.get(priority) || '';
 };
+
+/**
+ * @param {string} priorityLabel
+ * @return {string}
+ */
+Components.uiLabelToPriority = function(priorityLabel) {
+  var labelToPriorityMap = Components.uiLabelToPriority._uiLabelToPriorityMap;

[allada, 2016/12/27 18:52:51]

nit: Lets doctype this (above this line):

/** @type {!Map<string, !Protocol.Network.ResourcePriority>} */

+
+  if (labelToPriorityMap)
+    return labelToPriorityMap.get(priorityLabel);
+
+  labelToPriorityMap = new Map();
+  Components.priorityUiLabelMap().forEach((value, key) => labelToPriorityMap.set(value, key));
+  Components.uiLabelToPriority._uiLabelToPriorityMap = labelToPriorityMap;
+  return labelToPriorityMap.get(priorityLabel) || '';
+};
+
+/**
+ * @return {!Map<!Protocol.Network.ResourcePriority, string>}
+ */
+Components.priorityUiLabelMap = function() {
+  /** @type {!Map<!Protocol.Network.ResourcePriority, string>} */
+  var map = Components.priorityUiLabelMap._priorityUiLabelMap;
+
+  if (map)
+    return map;
+
+  map = new Map();
+  map.set(Protocol.Network.ResourcePriority.VeryLow, Common.UIString('Lowest'));
+  map.set(Protocol.Network.ResourcePriority.Low, Common.UIString('Low'));
+  map.set(Protocol.Network.ResourcePriority.Medium, Common.UIString('Medium'));
+  map.set(Protocol.Network.ResourcePriority.High, Common.UIString('High'));
+  map.set(Protocol.Network.ResourcePriority.VeryHigh, Common.UIString('Highest'));
+  Components.priorityUiLabelMap._priorityUiLabelMap = map;
+
+  return map;
+};
+
+/**
+ * @return {!Map<!Protocol.Network.ResourcePriority, number>}
+ */
+Components.prioritySymbolToNumericMap = function() {
+  /** @type {!Map<!Protocol.Network.ResourcePriority, number>} */
+  var priorityMap = Components.prioritySymbolToNumericMap._symbolicToNumericPriorityMap;
+
+  if (priorityMap)
+    return priorityMap;
+
+  priorityMap = new Map();
+  priorityMap.set(Protocol.Network.ResourcePriority.VeryLow, 1);
+  priorityMap.set(Protocol.Network.ResourcePriority.Low, 2);
+  priorityMap.set(Protocol.Network.ResourcePriority.Medium, 3);
+  priorityMap.set(Protocol.Network.ResourcePriority.High, 4);
+  priorityMap.set(Protocol.Network.ResourcePriority.VeryHigh, 5);
+  Components.prioritySymbolToNumericMap._symbolicToNumericPriorityMap = priorityMap;
+
+  return priorityMap;
+};