Fix disabling all break points from within the debug event callback.

test/mjsunit/regress/regress-crbug-432493.js

Index: test/mjsunit/regress/regress-crbug-432493.js
diff --git a/test/mjsunit/regress/regress-crbug-432493.js b/test/mjsunit/regress/regress-crbug-432493.js
new file mode 100644
index 0000000000000000000000000000000000000000..87c4f839821b07247b4309f0f1acaa6dce8fb1b1
--- /dev/null
+++ b/test/mjsunit/regress/regress-crbug-432493.js
@@ -0,0 +1,57 @@
+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --expose-debug-as debug
+
+function f() {
+  var a = 1;
+  var b = 2;
+  return a + b;
+}
+
+var exception = null;
+var break_count = 0;
+var throw_count = 0;
+
+function listener(event, exec_state, event_data, data) {
+  try {
+    if (event == Debug.DebugEvent.Break) {
+      break_count++;
+      // Disable all breakpoints from within the debug event callback.
+      Debug.debuggerFlags().breakPointsActive.setValue(false);
+    } else if (event = Debug.DebugEvent.Exception) {
+      throw_count++;
+      // Enable all breakpoints from within the debug event callback.
+      Debug.debuggerFlags().breakPointsActive.setValue(true);
+    }
+  } catch (e) {
+    exception = e;
+  }
+}
+
+Debug = debug.Debug;
+
+Debug.setListener(listener);
+Debug.setBreakOnException();
+Debug.setBreakPoint(f, 2);
+
+f();
+f();
+
+assertEquals(1, break_count);
+assertEquals(0, throw_count);
+
+// Trigger exception event.
+try { throw 1; } catch (e) {}
+
+f();
+f();
+
+Debug.setListener(null);
+Debug.clearBreakOnException();
+Debug.debuggerFlags().breakPointsActive.setValue(true);
+
+assertEquals(2, break_count);
+assertEquals(1, throw_count);
+assertNull(exception);