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 470 matching lines @@
     }
     return false;
   }
 };
 
 /**
  * @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;
+  var map = Components.priorityUiLabelMap();
+  return map.get(priority) || Common.UIString('Unknown');

[allada, 2016/12/20 01:35:00]

Lets just return empty string if no match (no need to wrap empty string in
Common.UIString())

+};
+
+/**
+ * @param {string} priorityLabel
+ * @return {string}
+ */
+Components.uiLabelToPriority = function(priorityLabel) {
+  var labelToPriorityMap = Components.uiLabelToPriority._uiLabelToPriorityMap;
+
+  if (labelToPriorityMap)
+    return labelToPriorityMap.get(priorityLabel);
+
+  labelToPriorityMap = Components.priorityUiLabelMap().inverse({regularMap: true});

[allada, 2016/12/20 01:35:00]

Lets use:

labelToPriorityMap = new Map();
Components.priorityUiLabelMap().forEach((value, key) =>
labelToPriorityMap.set(value, key));

+  Components.uiLabelToPriority._uiLabelToPriorityMap = labelToPriorityMap;
+  return labelToPriorityMap.get(priorityLabel) || '';
+};
+
+/**
+ * @return {!Map}

[allada, 2016/12/20 01:35:00]

nit: Incomplete definition

@return {!Map<!Protocol.Network.ResourcePriority, string>}

+ */
+Components.priorityUiLabelMap = function() {
+  var map = Components.priorityUiLabelMap._priorityUiLabelMap;
+
+  if (map)
+    return map;
+
+  map = new Map([

[allada, 2016/12/20 01:35:00]

nit: I am trying to doctype as much as possible, so can we doctype this (or
closure will not be smart enough to know what's inside it)? ie:

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

[allada, 2016/12/20 01:35:00]

nit: This code should look similar to the code below or code below should look
similar to this code. (I personally prefer below style, but up to you :-) )

+    [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.priorityUiLabelMap._priorityUiLabelMap = map;
+
+  return map;
+};
+
+/**
+ * @return {!Map}

[allada, 2016/12/20 01:35:00]

nit: Incomplete definition

@return {!Map<!Protocol.Network.ResourcePriority, numeric>}

+ */
+Components.symbolicToNumericMap = function() {

[allada, 2016/12/20 01:35:00]

Sorry, lets rename this: "prioritySymbolToNumericMap" (forgot this would be in
Components).

+  var priorityMap = Components.symbolicToNumericMap._symbolicToNumericPriorityMap;
+
+  if (!priorityMap) {

[allada, 2016/12/20 01:35:00]

nit: We use early returns when possible to reduce nested code. eg:

if (priorityMap)
  return priorityMap;

.. rest of code ...

+    Components.symbolicToNumericMap._symbolicToNumericPriorityMap = new Map();

[allada, 2016/12/20 01:35:00]

nit: I am trying to doctype as much as possible, so can we doctype this (or
closure will not be smart enough to know what's inside it)? ie:

/** @type {!Map<!Protocol.Network.ResourcePriority, number>} */
Components.symbolicToNumericMap._symbolicToNumericPriorityMap = new Map();

+    priorityMap = Components.symbolicToNumericMap._symbolicToNumericPriorityMap;
+    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);
   }
-  return labelMap.get(priority) || Common.UIString('Unknown');
+
+  return priorityMap;
 };