Update the list of supported IMEs when an IME is added or removed

This allows chrome://settings/inputMethods to show up-to-date IME
information without closing and reopening the settings window. For
example, when the language X is enabled on the device and a new
Chrome OS IME extension for the language X is installed, it'll
instantly show up in chrome://settings/inputMethods. The same happens
for Android IMEs installed via Play Store too.

BUG=867795,845079
TEST=Add 'Japanese' to the language list, open chrome://settings/inputMethods,
 install 'SKK Japanese Input' (extension IME) from Chrome Web Store, verify
 the IME entry ('SKK') shows up in the settings page immediately.
TEST=Go to extensions page, disable the SKK IME, verify 'SKK' disappears
 immediately.

Cq-Include-Trybots: luci.chromium.try:closure_compilation
Change-Id: I20f7586cd58e7d6c6f92f37c1f0b697d57d17d32
Reviewed-on: https://chromium-review.googlesource.com/1198106
Commit-Queue: Yusuke Sato <yusukes@chromium.org>
Reviewed-by: Michael Giuffrida <michaelpg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#588233}

chrome/browser/resources/settings/languages_page/languages.js

@@ -432,25 +432,7 @@ Polymer({
     }
 
     if (supportedInputMethods) {
-      // Populate the hash map of supported input methods.
-      for (let j = 0; j < supportedInputMethods.length; j++) {
-        const inputMethod = supportedInputMethods[j];
-        inputMethod.enabled = !!inputMethod.enabled;
-        inputMethod.isProhibitedByPolicy = !!inputMethod.isProhibitedByPolicy;
-        // Add the input method to the map of IDs.
-        this.supportedInputMethodMap_.set(inputMethod.id, inputMethod);
-        // Add the input method to the list of input methods for each language
-        // it supports.
-        for (let k = 0; k < inputMethod.languageCodes.length; k++) {
-          const languageCode = inputMethod.languageCodes[k];
-          if (!this.supportedLanguageMap_.has(languageCode))
-            continue;
-          if (!this.languageInputMethods_.has(languageCode))
-            this.languageInputMethods_.set(languageCode, [inputMethod]);
-          else
-            this.languageInputMethods_.get(languageCode).push(inputMethod);
-        }
-      }
+      this.createInputMethodModel_(supportedInputMethods);
     }
 
     let prospectiveUILanguage;
@@ -492,6 +474,37 @@ Polymer({
     this._setLanguages(model);
   },
 
+  /**
+   * Constructs the input method part of the languages model.
+   * @param {!Array<!chrome.languageSettingsPrivate.InputMethod>}
+   *     supportedInputMethods Input methods.
+   * @private
+   */
+  createInputMethodModel_: function(supportedInputMethods) {
+    assert(cr.isChromeOS);
+    // Populate the hash map of supported input methods.
+    this.supportedInputMethodMap_.clear();
+    this.languageInputMethods_.clear();
+    for (let j = 0; j < supportedInputMethods.length; j++) {
+      const inputMethod = supportedInputMethods[j];
+      inputMethod.enabled = !!inputMethod.enabled;
+      inputMethod.isProhibitedByPolicy = !!inputMethod.isProhibitedByPolicy;
+      // Add the input method to the map of IDs.
+      this.supportedInputMethodMap_.set(inputMethod.id, inputMethod);
+      // Add the input method to the list of input methods for each language
+      // it supports.
+      for (let k = 0; k < inputMethod.languageCodes.length; k++) {
+        const languageCode = inputMethod.languageCodes[k];
+        if (!this.supportedLanguageMap_.has(languageCode))
+          continue;
+        if (!this.languageInputMethods_.has(languageCode))
+          this.languageInputMethods_.set(languageCode, [inputMethod]);
+        else
+          this.languageInputMethods_.get(languageCode).push(inputMethod);
+      }
+    }
+  },
+
   /**
    * Returns a list of LanguageStates for each enabled language in the supported
    * languages list.
@@ -606,6 +619,23 @@ Polymer({
         });
   },
 
+  /** @private */
+  updateSupportedInputMethods_: function() {
+    assert(cr.isChromeOS);
+    const promise = new Promise(resolve => {
+      this.languageSettingsPrivate_.getInputMethodLists(function(lists) {
+        resolve(
+            lists.componentExtensionImes.concat(lists.thirdPartyExtensionImes));
+      });
+    });
+    promise.then(result => {
+      const supportedInputMethods = result;
+      this.createInputMethodModel_(supportedInputMethods);
+      this.set('languages.inputMethods.supported', supportedInputMethods);
+      this.updateEnabledInputMethods_();
+    });
+  },
+
   /** @private */
   updateEnabledInputMethods_: function() {
     assert(cr.isChromeOS);
@@ -950,12 +980,12 @@ Polymer({
 
   /** @param {string} id Added input method ID. */
   onInputMethodAdded_: function(id) {
-    this.updateEnabledInputMethods_();
+    this.updateSupportedInputMethods_();
   },
 
   /** @param {string} id Removed input method ID. */
   onInputMethodRemoved_: function(id) {
-    this.updateEnabledInputMethods_();
+    this.updateSupportedInputMethods_();
   },
   // </if>
 });