First try at removing ? from HTML.

sdk/lib/chrome/dart2js/chrome_dart2js.dart

Index: sdk/lib/chrome/dart2js/chrome_dart2js.dart
diff --git a/sdk/lib/chrome/dart2js/chrome_dart2js.dart b/sdk/lib/chrome/dart2js/chrome_dart2js.dart
index 2c416c4c77bb9b70c11009167930468a435172ed..e62156ef2bb74d3d8e20b8ff35c0b93445918063 100644
--- a/sdk/lib/chrome/dart2js/chrome_dart2js.dart
+++ b/sdk/lib/chrome/dart2js/chrome_dart2js.dart
@@ -253,7 +253,7 @@ class Event {
                 [void callback(List<Rule> rules)]) {
     // proxy the callback
     void __proxy_callback(List rules) {
-      if (?callback) {
+      if (callback != null) {
         List<Rule> __proxy_rules = new List<Rule>();
 
         for (Object o in rules)
@@ -282,7 +282,7 @@ class Event {
                                    void callback(List<Rule> rules)]) {
     // proxy the callback
     void __proxy_callback(List rules) {
-      if (?callback) {
+      if (callback != null) {
         List<Rule> __proxy_rules = new List<Rule>();
 
         for (Object o in rules)
@@ -398,43 +398,43 @@ class AppWindowCreateWindowOptions extends ChromeObject {
    * Public constructor
    */
   AppWindowCreateWindowOptions({String id, int defaultWidth, int defaultHeight, int defaultLeft, int defaultTop, int width, int height, int left, int top, int minWidth, int minHeight, int maxWidth, int maxHeight, String type, String frame, AppWindowBounds bounds, bool transparentBackground, bool hidden, bool singleton}) {
-    if (?id)
+    if (id != null)

[Anton Muhin, 2013/04/25 09:33:34]

that's most probably an error: imagine invocation like foo(null, 1, 2).

You will now treat this invocation as a no-arg as you'll see a null as a 1st
argument.  With nulls you should go opposite direction and check arguments from
the last to the first.

Let's fix it and continue with review.

[Andrei Mouravski, 2013/04/29 22:33:05]

Can you explain this? These are not positional optional arguments, so why does
it matter what order they go in?

Other places, sure, but here?

[Anton Muhin, 2013/04/30 12:55:13]

Yes, you're right, I was meaning positionals, sorry

On 2013/04/29 22:33:05, Andrei Mouravski wrote:

       this.id = id;
-    if (?defaultWidth)
+    if (defaultWidth != null)
       this.defaultWidth = defaultWidth;
-    if (?defaultHeight)
+    if (defaultHeight != null)
       this.defaultHeight = defaultHeight;
-    if (?defaultLeft)
+    if (defaultLeft != null)
       this.defaultLeft = defaultLeft;
-    if (?defaultTop)
+    if (defaultTop != null)
       this.defaultTop = defaultTop;
-    if (?width)
+    if (width != null)
       this.width = width;
-    if (?height)
+    if (height != null)
       this.height = height;
-    if (?left)
+    if (left != null)
       this.left = left;
-    if (?top)
+    if (top != null)
       this.top = top;
-    if (?minWidth)
+    if (minWidth != null)
       this.minWidth = minWidth;
-    if (?minHeight)
+    if (minHeight != null)
       this.minHeight = minHeight;
-    if (?maxWidth)
+    if (maxWidth != null)
       this.maxWidth = maxWidth;
-    if (?maxHeight)
+    if (maxHeight != null)
       this.maxHeight = maxHeight;
-    if (?type)
+    if (type != null)
       this.type = type;
-    if (?frame)
+    if (frame != null)
       this.frame = frame;
-    if (?bounds)
+    if (bounds != null)
       this.bounds = bounds;
-    if (?transparentBackground)
+    if (transparentBackground != null)
       this.transparentBackground = transparentBackground;
-    if (?hidden)
+    if (hidden != null)
       this.hidden = hidden;
-    if (?singleton)
+    if (singleton != null)
       this.singleton = singleton;
   }
 
@@ -601,13 +601,13 @@ class AppWindowBounds extends ChromeObject {
    * Public constructor
    */
   AppWindowBounds({int left, int top, int width, int height}) {
-    if (?left)
+    if (left != null)
       this.left = left;
-    if (?top)
+    if (top != null)
       this.top = top;
-    if (?width)
+    if (width != null)
       this.width = width;
-    if (?height)
+    if (height != null)
       this.height = height;
   }
 
@@ -835,7 +835,7 @@ class API_app_window {
               [AppWindowCreateWindowOptions options,
               void callback(AppWindowAppWindow created_window)]) {
     void __proxy_callback(created_window) {
-      if (?callback)
+      if (callback != null)
         callback(new AppWindowAppWindow._proxy(created_window));
     }
     JS('void', '#.create(#, #, #)', this._jsObject, url, convertArgument(options),
@@ -923,9 +923,9 @@ class AppRuntimeLaunchItem extends ChromeObject {
    * Public constructor
    */
   AppRuntimeLaunchItem({FileEntry entry, String type}) {
-    if (?entry)
+    if (entry != null)
       this.entry = entry;
-    if (?type)
+    if (type != null)
       this.type = type;
   }
 
@@ -958,11 +958,11 @@ class AppRuntimeLaunchData extends ChromeObject {
    * Public constructor
    */
   AppRuntimeLaunchData({AppRuntimeIntent intent, String id, List<AppRuntimeLaunchItem> items}) {
-    if (?intent)
+    if (intent != null)
       this.intent = intent;
-    if (?id)
+    if (id != null)
       this.id = id;
-    if (?items)
+    if (items != null)
       this.items = items;
   }
 
@@ -1006,11 +1006,11 @@ class AppRuntimeIntentResponse extends ChromeObject {
    * Public constructor
    */
   AppRuntimeIntentResponse({int intentId, bool success, Object data}) {
-    if (?intentId)
+    if (intentId != null)
       this.intentId = intentId;
-    if (?success)
+    if (success != null)
       this.success = success;
-    if (?data)
+    if (data != null)
       this.data = data;
   }
 
@@ -1054,7 +1054,7 @@ class AppRuntimeIntentResponse extends ChromeObject {
 class Event_app_runtime_onLaunched extends Event {
   void addListener(void callback(AppRuntimeLaunchData launchData)) {
     void __proxy_callback(launchData) {
-      if (?callback) {
+      if (callback != null) {
         callback(new AppRuntimeLaunchData._proxy(launchData));
       }
     }
@@ -1063,7 +1063,7 @@ class Event_app_runtime_onLaunched extends Event {
 
   void removeListener(void callback(AppRuntimeLaunchData launchData)) {
     void __proxy_callback(launchData) {
-      if (?callback) {
+      if (callback != null) {
         callback(new AppRuntimeLaunchData._proxy(launchData));
       }
     }
@@ -1072,7 +1072,7 @@ class Event_app_runtime_onLaunched extends Event {
 
   bool hasListener(void callback(AppRuntimeLaunchData launchData)) {
     void __proxy_callback(launchData) {
-      if (?callback) {
+      if (callback != null) {
         callback(new AppRuntimeLaunchData._proxy(launchData));
       }
     }