Update documentation on .fromEnvironment. Make bool default be false.

sdk/lib/core/int.dart

Index: sdk/lib/core/int.dart
diff --git a/sdk/lib/core/int.dart b/sdk/lib/core/int.dart
index 1c17a317b39002935fe4c7d65be09445ce2309d4..c06a3ee0f8d9fb40438055905a7db2cf1fa3bada 100644
--- a/sdk/lib/core/int.dart
+++ b/sdk/lib/core/int.dart
@@ -19,6 +19,20 @@ part of dart.core;
  */
 abstract class int extends num {
   /**
+   * Returns the integer value of the given environment declaration [name].
+   *
+   * The result is the same as would be returned by:
+   *
+   *     int.parse(const String.fromEnvironment(name, defaultValue: ""),
+   *               (_) => defaultValue)
+   *
+   * Example:
+   *
+   *     const int.fromEnvironment("defaultPort", defaultValue: 80)
+   */
+  external const factory int.fromEnvironment(String name, {int defaultValue});
+
+  /**
    * Bit-wise and operator.
    *
    * Treating both `this` and [other] as sufficiently large two's component
@@ -252,12 +266,4 @@ abstract class int extends num {
   external static int parse(String source,
                             { int radix,
                               int onError(String source) });
-
-  /**
-   * Returns the integer value for the given environment variable
-   * [name] or [defaultValue] if [name] is not present. If the value
-   * of the environment variable is not a valid integer literal a
-   * [FormatException] is thrown.
-   */
-  external const factory int.fromEnvironment(String name, {int defaultValue});
 }