Dart: Removes C++ set for closing handles on an unhandled exception.

mojo/public/dart/mojo/sdk_ext/src/natives.dart

Index: mojo/public/dart/mojo/sdk_ext/src/natives.dart
diff --git a/mojo/public/dart/mojo/sdk_ext/src/natives.dart b/mojo/public/dart/mojo/sdk_ext/src/natives.dart
index 236069efdcbf3c431f211cf9714c88aab69983a3..a9ec169ab442a9319f3f5bc02182256c3f98dad5 100644
--- a/mojo/public/dart/mojo/sdk_ext/src/natives.dart
+++ b/mojo/public/dart/mojo/sdk_ext/src/natives.dart
@@ -9,13 +9,39 @@ class MojoCoreNatives {
 }
 
 class MojoHandleNatives {
-  static int register(Object eventStream, int handle)
-      native "MojoHandle_Register";
+  static Set<int> _unclosedHandles = new Set<int>();

[Cutch, 2015/10/26 17:10:03]

This is redundant with the code in handle.dart. We are now keeping two sets of
unclosed handles. One under assert the other (being added in this CL) is
unconditional.

This set should become the  map from handle  to _HandleCreationRecord.
_HandleCreationRecord can still only grab the stack trace under certain
conditions (assert for now).

Then you can kill the code in handle.dart (or vice versa).

[zra, 2015/10/26 17:53:54]

Yah. This CL was getting big, so I'm going to do this in two CLs. Added TODO in
handle.dart.

+
+  static void addUnclosed(int handle) {
+    _unclosedHandles.add(handle);
+  }
+
+  static void removeUnclosed(int handle) {
+    _unclosedHandles.remove(handle);
+  }
+
+  static int registerFinalizer(Object eventStream, int handle)
+      native "MojoHandle_RegisterFinalizer";
+
   static int close(int handle) native "MojoHandle_Close";
+
   static List wait(int handle, int signals, int deadline)
       native "MojoHandle_Wait";
+
   static List waitMany(List<int> handles, List<int> signals, int deadline)
       native "MojoHandle_WaitMany";
+
+  // Called from the embedder's unhandled exception callback.
+  // Returns the number of successfully closed handles.
+  static int _closeUnclosedHandles() {
+    int count = 0;
+    _unclosedHandles.forEach((h) {
+      if (MojoHandleNatives.close(h) == 0) {
+        count++;
+      }
+    });
+    _unclosedHandles.clear();
+    return count;
+  }
 }
 
 class MojoHandleWatcherNatives {