Only inject ChromeVox classic when necessary.

chrome/browser/resources/chromeos/chromevox/chromevox/background/background.js

Index: chrome/browser/resources/chromeos/chromevox/chromevox/background/background.js
diff --git a/chrome/browser/resources/chromeos/chromevox/chromevox/background/background.js b/chrome/browser/resources/chromeos/chromevox/chromevox/background/background.js
index c6730e45324b7defac1d0aab02cc2f9393fc98bb..f3b0d24390c680da0acdec1ee05e133f51b7ba2c 100644
--- a/chrome/browser/resources/chromeos/chromevox/chromevox/background/background.js
+++ b/chrome/browser/resources/chromeos/chromevox/chromevox/background/background.js
@@ -104,34 +104,6 @@ cvox.ChromeVoxBackground.prototype.init = function() {
         this.onLoadStateChanged);
   }
 
-  var listOfFiles;
-
-  // These lists of files must match the content_scripts section in
-  // the manifest files.
-  if (COMPILED) {
-    listOfFiles = ['chromeVoxChromePageScript.js'];
-  } else {
-    listOfFiles = [
-        'closure/closure_preinit.js',
-        'closure/base.js',
-        'deps.js',
-        'chromevox/injected/loader.js'];
-  }
-
-  var self = this;
-  var stageTwo = function(code) {
-    // Inject the content script into all running tabs.
-    chrome.windows.getAll({'populate': true}, function(windows) {
-      for (var i = 0; i < windows.length; i++) {
-        var tabs = windows[i].tabs;
-        for (var j = 0; j < tabs.length; j++) {
-          var tab = tabs[j];
-          self.injectChromeVoxIntoTab(tab, listOfFiles, code);
-        }
-      }
-    });
-  };
-
   this.checkVersionNumber();
 
   // Set up a message passing system for goog.provide() calls from
@@ -149,10 +121,22 @@ cvox.ChromeVoxBackground.prototype.init = function() {
         return true;
       });
 
-  // We use fetchCode instead of chrome.extensions.executeFile because
-  // executeFile doesn't propagate the file name to the content script
-  // which means that script is not visible in Dev Tools.
-  cvox.InjectedScriptLoader.fetchCode(listOfFiles, stageTwo);
+  var self = this;
+  if (chrome.commandLinePrivate) {
+    chrome.commandLinePrivate.hasSwitch('enable-chromevox-next',
+        goog.bind(function(result) {
+            if (result) {
+              return;
+            }
+            // Inject the content script into all running tabs.
+            chrome.windows.getAll({'populate': true}, function(windows) {
+              for (var i = 0; i < windows.length; i++) {
+                var tabs = windows[i].tabs;
+                self.injectChromeVoxIntoTabs(tabs);
+              }
+            });
+        }, this));
+  }
 
   if (localStorage['active'] == 'false') {
     // Warn the user when the browser first starts if ChromeVox is inactive.
@@ -168,56 +152,79 @@ cvox.ChromeVoxBackground.prototype.init = function() {
 
 /**
  * Inject ChromeVox into a tab.
- * @param {Tab} tab The tab where ChromeVox scripts should be injected.
- * @param {Array.<string>} files The files to load.
- * @param {Object.<string, string>} code The contents of the files.
+ * @param {Array.<Tab>} tabs The tab where ChromeVox scripts should be injected.
+ * @param {boolean=} opt_forceCompiled forces compiled ChromeVox to be injected;
+ * defaults to Closure's compiled flag.
  */
-cvox.ChromeVoxBackground.prototype.injectChromeVoxIntoTab =
-    function(tab, files, code) {
-  window.console.log('Injecting into ' + tab.id, tab);
-  var sawError = false;
+cvox.ChromeVoxBackground.prototype.injectChromeVoxIntoTabs =
+    function(tabs, opt_forceCompiled) {
+  var listOfFiles;
 
-  /**
-   * A helper function which executes code.
-   * @param {string} code The code to execute.
-   */
-  var executeScript = goog.bind(function(code) {
-    chrome.tabs.executeScript(
-        tab.id,
-        {'code': code,
-         'allFrames': true},
-        goog.bind(function() {
-          if (!chrome.extension.lastError) {
-            return;
-          }
-          if (sawError) {
-            return;
-          }
-          sawError = true;
-          console.error('Could not inject into tab', tab);
-          this.tts.speak('Error starting ChromeVox for ' +
-              tab.title + ', ' + tab.url, 1);
-        }, this));
-  }, this);
-
-  // There is a scenario where two copies of the content script can get
-  // loaded into the same tab on browser startup - one automatically
-  // and one because the background page injects the content script into
-  // every tab on startup. To work around potential bugs resulting from this,
-  // ChromeVox exports a global function called disableChromeVox() that can
-  // be used here to disable any existing running instance before we inject
-  // a new instance of the content script into this tab.
-  //
-  // It's harmless if there wasn't a copy of ChromeVox already running.
-  //
-  // Also, set some variables so that Closure deps work correctly and so
-  // that ChromeVox knows not to announce feedback as if a page just loaded.
-  executeScript('try { window.disableChromeVox(); } catch(e) { }\n' +
-                'window.INJECTED_AFTER_LOAD = true;\n' +
-                'window.CLOSURE_NO_DEPS = true\n');
-
-  // Now inject the ChromeVox content script code into the tab.
-  files.forEach(function(file) { executeScript(code[file]); });
+  // These lists of files must match the content_scripts section in
+  // the manifest files.
+  if (COMPILED || opt_forceCompiled) {
+    listOfFiles = ['chromeVoxChromePageScript.js'];
+  } else {
+    listOfFiles = [
+        'closure/closure_preinit.js',
+        'closure/base.js',
+        'deps.js',
+        'chromevox/injected/loader.js'];
+  }
+
+  var stageTwo = function(code) {
+    for (var i = 0, tab; tab = tabs[i]; i++) {
+      window.console.log('Injecting into ' + tab.id, tab);
+      var sawError = false;
+
+      /**
+       * A helper function which executes code.
+       * @param {string} code The code to execute.
+       */
+      var executeScript = goog.bind(function(code) {
+        chrome.tabs.executeScript(
+            tab.id,
+            {'code': code,
+             'allFrames': true},
+            goog.bind(function() {
+              if (!chrome.extension.lastError) {
+                return;
+              }
+              if (sawError) {
+                return;
+              }
+              sawError = true;
+              console.error('Could not inject into tab', tab);
+              this.tts.speak('Error starting ChromeVox for ' +
+                  tab.title + ', ' + tab.url, 1);
+            }, this));
+      }, this);
+
+      // There is a scenario where two copies of the content script can get
+      // loaded into the same tab on browser startup - one automatically and one
+      // because the background page injects the content script into every tab
+      // on startup. To work around potential bugs resulting from this,
+      // ChromeVox exports a global function called disableChromeVox() that can
+      // be used here to disable any existing running instance before we inject
+      // a new instance of the content script into this tab.
+      //
+      // It's harmless if there wasn't a copy of ChromeVox already running.
+      //
+      // Also, set some variables so that Closure deps work correctly and so
+      // that ChromeVox knows not to announce feedback as if a page just loaded.
+      executeScript('try { window.disableChromeVox(); } catch(e) { }\n' +
+          'window.INJECTED_AFTER_LOAD = true;\n' +
+          'window.CLOSURE_NO_DEPS = true\n');
+
+      // Now inject the ChromeVox content script code into the tab.
+      listOfFiles.forEach(function(file) { executeScript(code[file]); });
+    }
+  };
+
+  // We use fetchCode instead of chrome.extensions.executeFile because
+  // executeFile doesn't propagate the file name to the content script
+  // which means that script is not visible in Dev Tools.
+  cvox.InjectedScriptLoader.fetchCode(listOfFiles, stageTwo);
 };
 
 
@@ -543,4 +550,7 @@ cvox.ChromeVoxBackground.prototype.onLoadStateChanged = function(
 
   // Export the braille object for access by the options page.
   window['braille'] = cvox.ChromeVox.braille;
+
+  // Export this background page for ChromeVox Next to access.
+  cvox.ChromeVox.background = background;
 })();