[tools] Add link_click chrome extension

This extension imitates user-interaction on a page by randomly clicking on
links matching a given regexp pattern.

Change-Id: I210bebf36ce6e3a3c785953010ce21528093d1af
NOTRY=true

Change-Id: I210bebf36ce6e3a3c785953010ce21528093d1af
Reviewed-on: https://chromium-review.googlesource.com/500247
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45201}

tools/link_clicker.extension/README.txt

+This extension can be used to repro infrequent crashers on an unclear url-set
+for a given domain. It follows a random link that matches a predefined pattern,
+imitating something like real user interaction on a page.
+
+Usage:
+1. Open chrome://extensions
+2. Enable developer mode
+3. Click "Load unpacked extension"
+4. Click the orange link-clicker extension button in the toolbar
+5. Set the parameters and click "Enable" to start following links on all tabs
+   open in the current window. Beware, this extension will follow arbitrary
+   links. You probably don't want to be logged in with any important account.

tools/link_clicker.extension/background.js

+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+(function linkClickerBackgroundScript() {
+
+  // time in ms.
+  let minInterval = 1*1000;
+  let maxInterval = 20*1000;
+  let pattern = /.*/;
+  let enabled = false;
+
+  let animateIconIntervalId;
+
+  // ===========================================================================
+
+  chrome.runtime.onMessage.addListener(function(msg, sender, response) {
+    let result;
+    if (msg.type == 'update') result = updateFromMessage(msg);
+    if (msg.type == 'get') result = getValues();
+    response(result);
+  });
+
+  // ===========================================================================
+  function updateFromMessage(msg) {
+    console.log(msg);
+    minInterval = Number(msg.minInterval)
+    maxInterval = Number(msg.maxInterval);
+    if (maxInterval < minInterval) {
+      let tmpMin = Math.min(minInterval, maxInterval);
+      maxInterval = Math.max(minInterval, maxInterval);
+      minInterval = tmpMin;
+    }
+    pattern = new RegExp(msg.pattern);
+    enabled = Boolean(msg.enabled);
+    updateTabs();
+    scheduleIconAnimation();
+    return getValues();
+  }
+
+  function getValues() {
+    return {
+      type: 'update',
+      minInterval: minInterval,
+      maxInterval: maxInterval,
+      pattern: pattern.source,
+      enabled: enabled
+    }
+  }
+
+  function updateTabs() {
+    chrome.tabs.query({active: true, currentWindow: true}, function(tabs) {
+      let message = getValues();
+      for (let i = 0; i < tabs.length; ++i) {
+        chrome.tabs.sendMessage(tabs[i].id, message);
+      }
+    });
+  }
+
+  let animationIndex = 0;
+  function animateIcon() {
+    animationIndex = (animationIndex + 1) % 4;
+    chrome.browserAction.setBadgeText( { text: ".".repeat(animationIndex) } );
+  }
+
+  function scheduleIconAnimation() {
+    chrome.browserAction.setBadgeText( { text: "" } );
+    clearInterval(animateIconIntervalId);
+    if (enabled) {
+      animateIconIntervalId = setInterval(animateIcon, 500);
+    }
+  }
+
+})();

tools/link_clicker.extension/content.js

+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+(function linkClickerContentScript() {
+  // time in ms
+  let minInterval;
+  let maxInterval;
+  let pattern;
+  let enabled;
+  let timeoutId;
+
+  // Initialize variables.
+  chrome.runtime.sendMessage({type:'get'}, function(msg) {
+    if (msg.type == 'update') updateFromMessage(msg);
+  });
+
+  chrome.runtime.onMessage.addListener(
+    function(msg, sender, sendResponse) {
+      if (msg.type == 'update') updateFromMessage(msg);
+    });
+
+  function findAllLinks() {
+    let links = document.links;
+    let results = new Set();
+    for (let i = 0; i < links.length; i++) {
+      let href = links[i].href;
+      if (!href) continue;
+      if (href && href.match(pattern)) results.add(href);
+    }
+    return Array.from(results);
+  }
+
+  function updateFromMessage(msg) {
+    console.log(msg);
+    minInterval = Number(msg.minInterval)
+    maxInterval = Number(msg.maxInterval);
+    pattern = new RegExp(msg.pattern);
+    enabled = Boolean(msg.enabled);
+    if (enabled) schedule();
+  }
+
+  function followLink() {
+    if (!enabled) return;
+    let links = findAllLinks();
+    if (links.length <= 5) {
+      // navigate back if the page has not enough links
+      window.history.back()
+      console.log("navigate back");
+    } else {
+      let link = links[Math.round(Math.random() * (links.length-1))];
+      console.log(link);
+      window.location.href = link;
+      // Schedule in case we just followed an anchor.
+      schedule();
+    }
+  }
+
+  function schedule() {
+    clearTimeout(timeoutId);
+    let delta = maxInterval - minInterval;
+    let duration = minInterval + (Math.random() * delta);
+    console.log(duration);
+    timeoutId = setTimeout(followLink, duration);
+  }
+})();

tools/link_clicker.extension/manifest.json

+{
+  "name": "A browser action with a popup that automatically clicks links matching a regexp",
+  "description": "Follow links",
+  "version": "1.0",
+  "permissions": [
+    "tabs", "http://*/*", "https://*/*"
+  ],
+  "background": { "scripts": ["background.js"] },
+  "browser_action": {
+      "default_title": "Follow links.",
+      "default_icon": "icon.png",
+      "default_popup": "popup.html"
+  },
+  "content_scripts": [
+    {
+      "matches": ["http://*/*", "https://*/*"],
+      "js": ["content.js"]
+    }
+  ],
+  "manifest_version": 2
+}

tools/link_clicker.extension/popup.html

+<!doctype html>
+<!--
+Copyright 2017 the V8 project authors. All rights reserved.
+Use of this source code is governed by a BSD-style license that can be
+found in the LICENSE file.
+-->
+<html>
+  <head>
+    <style>
+    body {
+      overflow: hidden;
+      padding: 5px;
+      width: 310px;
+    }
+    input, textarea, select, button {
+      width : 300px;
+      margin: 0;
+      box-sizing: border-box;
+    }
+    label {
+      clear: both;
+    }
+    </style>
+    <script src="popup.js"></script>
+  </head>
+  <body>
+    <form>
+      <p>
+        <label>Min click-interval <span id="minIntervalValue"></span>:
+          <input type="range" id="minInterval" min="1000" max="60000">
+        </label>
+      </p>
+      <p>
+        <label> Max click-interval <span id="maxIntervalValue"></span>:
+          <input type="range" id="maxInterval" min="1000" max="60000">
+        </label>
+      </p>
+      <p>
+        <label>Link regexp:
+          <input type="input" id="pattern" >
+        </label>
+      </p>
+      <p>
+        <label>Enable:
+          <input type="checkbox" id="enabled" >
+        </label>
+      </p>
+    </form>
+  </body>
+</html>

tools/link_clicker.extension/popup.js

+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+function $(id) {
+  return document.querySelector(id);
+}
+
+// ===========================================================================
+document.addEventListener('DOMContentLoaded', function () {
+  installFormChangeHandler()
+});
+
+
+function installFormChangeHandler() {
+  initForm();
+  let inputs = document.getElementsByTagName("input");
+  for (let i = 0; i < inputs.length; i++){
+     inputs[i].onchange = onFormChange;
+  }
+}
+
+function initForm() {
+  chrome.runtime.sendMessage({type:'get'}, function(response) {
+    updateFromMessage(response);
+  });
+}
+// ===========================================================================
+
+function updateFromMessage(msg) {
+  $("#minInterval").value = msg.minInterval;
+  $("#maxInterval").value = msg.maxInterval;
+  $("#pattern").value = msg.pattern;
+  $("#enabled").checked = msg.enabled;
+  $("#minIntervalValue").innerText = msg.minInterval+"ms";
+  $("#maxIntervalValue").innerText = msg.maxInterval+"ms";
+}
+
+function onFormChange() {
+  let minInterval = $("#minInterval").value;
+  let maxInterval = $("#maxInterval").value;
+
+  let message = {
+    type: 'update',
+    minInterval: minInterval,
+    maxInterval: maxInterval,
+    pattern: $("#pattern").value,
+    enabled: $("#enabled").checked
+  }
+  chrome.runtime.sendMessage(message, function(response) {
+    updateFromMessage(response);
+  });
+}