Bug 1503070 part 12. Stop using DOMRequest in BrowserElement getCanGoForward/Back APIs. r=ehsan

dom/browser-element/BrowserElementParent.js

@@ -49,18 +49,18 @@ function defineNoReturnMethod(fn) {
   };
 }
 
-function defineDOMRequestMethod(msgName) {
+function definePromiseMethod(msgName) {
   return function() {
-    return this._sendDOMRequest(msgName);
+    return this._sendAsyncRequest(msgName);
   };
 }
 
 function BrowserElementParent() {
   debug("Creating new BrowserElementParent object");
-  this._domRequestCounter = 0;
+  this._promiseCounter = 0;
   this._domRequestReady = false;
   this._pendingAPICalls = [];
-  this._pendingDOMRequests = {};
+  this._pendingPromises = {};
   this._pendingDOMFullscreen = false;
 
   Services.obs.addObserver(this, 'oop-frameloader-crashed', /* ownsWeak = */ true);
@@ -156,8 +156,8 @@ BrowserElementParent.prototype = {
       "error": this._fireEventFromMsg,
       "firstpaint": this._fireProfiledEventFromMsg,
       "documentfirstpaint": this._fireProfiledEventFromMsg,
-      "got-can-go-back": this._gotDOMRequestResult,
-      "got-can-go-forward": this._gotDOMRequestResult,
+      "got-can-go-back": this._gotAsyncResult,
+      "got-can-go-forward": this._gotAsyncResult,
       "requested-dom-fullscreen": this._requestedDOMFullscreen,
       "fullscreen-origin-change": this._fullscreenOriginChange,
       "exit-dom-fullscreen": this._exitDomFullscreen,
@@ -441,29 +441,33 @@ BrowserElementParent.prototype = {
   },
 
   /**
-   * Kick off a DOMRequest in the child process.
+   * Kick off an async operation in the child process.
    *
-   * We'll fire an event called |msgName| on the child process, passing along
+   * We'll send a message called |msgName| to the child process, passing along
    * an object with two fields:
    *
-   *  - id:  the ID of this request.
-   *  - arg: arguments to pass to the child along with this request.
+   *  - id:  the ID of this async call.
+   *  - arg: arguments to pass to the child along with this async call.
    *
    * We expect the child to pass the ID back to us upon completion of the
-   * request.  See _gotDOMRequestResult.
+   * call.  See _gotAsyncResult.
    */
-  _sendDOMRequest: function(msgName, args) {
-    let id = 'req_' + this._domRequestCounter++;
-    let req = Services.DOMRequest.createRequest(this._window);
+  _sendAsyncRequest: function(msgName, args) {
+    let id = 'req_' + this._promiseCounter++;
+    let resolve, reject;
+    let p = new this._window.Promise((res, rej) => {
+      resolve = res;
+      reject = rej;
+    });
     let self = this;
     let send = function() {
       if (!self._isAlive()) {
         return;
       }
       if (self._sendAsyncMsg(msgName, {id: id, args: args})) {
-        self._pendingDOMRequests[id] = req;
+        self._pendingPromises[id] = { p, resolve, reject };
       } else {
-        Services.DOMRequest.fireErrorAsync(req, "fail");
+        reject(new this._window.DOMException("fail"));
       }
     };
     if (this._domRequestReady) {
@@ -472,35 +476,35 @@ BrowserElementParent.prototype = {
       // Child haven't been loaded.
       this._pendingAPICalls.push(send);
     }
-    return req;
+    return p;
   },
 
   /**
-   * Called when the child process finishes handling a DOMRequest.  data.json
-   * must have the fields [id, successRv], if the DOMRequest was successful, or
-   * [id, errorMsg], if the request was not successful.
+   * Called when the child process finishes handling an async call.  data.json
+   * must have the fields [id, successRv], if the async call was successful, or
+   * [id, errorMsg], if the call was not successful.
    *
    * The fields have the following meanings:
    *
-   *  - id:        the ID of the DOM request (see _sendDOMRequest)
-   *  - successRv: the request's return value, if the request succeeded
-   *  - errorMsg:  the message to pass to DOMRequest.fireError(), if the request
-   *               failed.
+   *  - id:        the ID of the async call (see _sendAsyncRequest)
+   *  - successRv: the call's return value, if the call succeeded
+   *  - errorMsg:  the message to pass to the Promise reject callback, if the
+   *               call failed.
    *
    */
-  _gotDOMRequestResult: function(data) {
-    let req = this._pendingDOMRequests[data.json.id];
-    delete this._pendingDOMRequests[data.json.id];
+  _gotAsyncResult: function(data) {
+    let p = this._pendingPromises[data.json.id];
+    delete this._pendingPromises[data.json.id];
 
     if ('successRv' in data.json) {
-      debug("Successful gotDOMRequestResult.");
+      debug("Successful gotAsyncResult.");
       let clientObj = Cu.cloneInto(data.json.successRv, this._window);
-      Services.DOMRequest.fireSuccess(req, clientObj);
+      p.resolve(clientObj);
     }
     else {
-      debug("Got error in gotDOMRequestResult.");
-      Services.DOMRequest.fireErrorAsync(req,
-        Cu.cloneInto(data.json.errorMsg, this._window));
+      debug("Got error in gotAsyncResult.");
+      p.reject(new this._window.DOMException(
+        Cu.cloneInto(data.json.errorMsg, this._window)));
     }
   },
 
@@ -532,8 +536,8 @@ BrowserElementParent.prototype = {
     });
   }),
 
-  getCanGoBack: defineDOMRequestMethod('get-can-go-back'),
-  getCanGoForward: defineDOMRequestMethod('get-can-go-forward'),
+  getCanGoBack: definePromiseMethod('get-can-go-back'),
+  getCanGoForward: definePromiseMethod('get-can-go-forward'),
 
   goBack: defineNoReturnMethod(function() {
     this._sendAsyncMsg('go-back');

dom/browser-element/mochitest/browserElement_BackForward.js

@@ -32,20 +32,20 @@ function runTest() {
 
 function checkCanGoBackAndForward(canGoBack, canGoForward, nextTest) {
   var seenCanGoBackResult = false;
-  iframe.getCanGoBack().onsuccess = function(e) {
+  iframe.getCanGoBack().then(function(result) {
     is(seenCanGoBackResult, false, "onsuccess handler shouldn't be called twice.");
     seenCanGoBackResult = true;
-    is(e.target.result, canGoBack);
+    is(result, canGoBack);
     maybeRunNextTest();
-  };
+  });
 
   var seenCanGoForwardResult = false;
-  iframe.getCanGoForward().onsuccess = function(e) {
+  iframe.getCanGoForward().then(function(result) {
     is(seenCanGoForwardResult, false, "onsuccess handler shouldn't be called twice.");
     seenCanGoForwardResult = true;
-    is(e.target.result, canGoForward);
+    is(result, canGoForward);
     maybeRunNextTest();
-  };
+  });
 
   function maybeRunNextTest() {
     if (seenCanGoBackResult && seenCanGoForwardResult) {

dom/browser-element/nsIBrowserElementAPI.idl

@@ -6,7 +6,6 @@
 
 #include "nsISupports.idl"
 
-webidl DOMRequest;
 webidl FrameLoader;
 
 %{C++
@@ -40,6 +39,6 @@ interface nsIBrowserElementAPI : nsISupports
   void goForward();
   void reload(in boolean hardReload);
   void stop();
-  DOMRequest getCanGoBack();
-  DOMRequest getCanGoForward();
+  Promise getCanGoBack();
+  Promise getCanGoForward();
 };

dom/html/nsBrowserElement.cpp

@@ -9,7 +9,7 @@
 #include "mozilla/Preferences.h"
 #include "mozilla/Services.h"
 #include "mozilla/dom/BrowserElementBinding.h"
-#include "mozilla/dom/DOMRequest.h"
+#include "mozilla/dom/Promise.h"
 #include "mozilla/dom/ScriptSettings.h"
 #include "mozilla/dom/ToJSValue.h"
 
@@ -134,36 +134,36 @@ nsBrowserElement::Stop(ErrorResult& aRv)
   }
 }
 
-already_AddRefed<DOMRequest>
+already_AddRefed<Promise>
 nsBrowserElement::GetCanGoBack(ErrorResult& aRv)
 {
   NS_ENSURE_TRUE(IsBrowserElementOrThrow(aRv), nullptr);
 
-  RefPtr<DOMRequest> req;
-  nsresult rv = mBrowserElementAPI->GetCanGoBack(getter_AddRefs(req));
+  RefPtr<Promise> p;
+  nsresult rv = mBrowserElementAPI->GetCanGoBack(getter_AddRefs(p));
 
   if (NS_WARN_IF(NS_FAILED(rv))) {
     aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
     return nullptr;
   }
 
-  return req.forget();
+  return p.forget();
 }
 
-already_AddRefed<DOMRequest>
+already_AddRefed<Promise>
 nsBrowserElement::GetCanGoForward(ErrorResult& aRv)
 {
   NS_ENSURE_TRUE(IsBrowserElementOrThrow(aRv), nullptr);
 
-  RefPtr<DOMRequest> req;
-  nsresult rv = mBrowserElementAPI->GetCanGoForward(getter_AddRefs(req));
+  RefPtr<Promise> p;
+  nsresult rv = mBrowserElementAPI->GetCanGoForward(getter_AddRefs(p));
 
   if (NS_WARN_IF(NS_FAILED(rv))) {
     aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
     return nullptr;
   }
 
-  return req.forget();
+  return p.forget();
 }
 
 } // namespace mozilla

dom/html/nsBrowserElement.h

@@ -17,7 +17,7 @@ class nsFrameLoader;
 namespace mozilla {
 
 namespace dom {
-class DOMRequest;
+class Promise;
 } // namespace dom
 
 class ErrorResult;
@@ -43,8 +43,8 @@ public:
   void Reload(bool aHardReload, ErrorResult& aRv);
   void Stop(ErrorResult& aRv);
 
-  already_AddRefed<dom::DOMRequest> GetCanGoBack(ErrorResult& aRv);
-  already_AddRefed<dom::DOMRequest> GetCanGoForward(ErrorResult& aRv);
+  already_AddRefed<dom::Promise> GetCanGoBack(ErrorResult& aRv);
+  already_AddRefed<dom::Promise> GetCanGoForward(ErrorResult& aRv);
 
 protected:
   NS_IMETHOD_(already_AddRefed<nsFrameLoader>) GetFrameLoader() = 0;

dom/webidl/BrowserElement.webidl

@@ -45,10 +45,10 @@ interface BrowserElementPrivileged {
   [Throws,
    Pref="dom.mozBrowserFramesEnabled",
    ChromeOnly]
-  DOMRequest getCanGoBack();
+  Promise<boolean> getCanGoBack();
 
   [Throws,
    Pref="dom.mozBrowserFramesEnabled",
    ChromeOnly]
-  DOMRequest getCanGoForward();
+  Promise<boolean> getCanGoForward();
 };