Fix typos in InternalPreconditions.

Change-Id: Idd109f7daade9dbdfa7676af421137489b8ebf2c
diff --git a/user/super/com/google/gwt/emul/javaemul/internal/InternalPreconditions.java b/user/super/com/google/gwt/emul/javaemul/internal/InternalPreconditions.java
index 15e064b..540f110 100644
--- a/user/super/com/google/gwt/emul/javaemul/internal/InternalPreconditions.java
+++ b/user/super/com/google/gwt/emul/javaemul/internal/InternalPreconditions.java
@@ -237,10 +237,10 @@
    */
   public static void checkState(boolean expression) {
     if (API_CHECK) {
-      checkCritcalState(expression);
+      checkCriticalState(expression);
     } else if (CHECKED_MODE) {
       try {
-        checkCritcalState(expression);
+        checkCriticalState(expression);
       } catch (Exception e) {
         throw new AssertionError(e);
       }
@@ -254,7 +254,7 @@
    * For cases where failing fast is pretty important and not failing early could cause bugs that
    * are much harder to debug.
    */
-  public static void checkCritcalState(boolean expression) {
+  public static void checkCriticalState(boolean expression) {
     if (!expression) {
       throw new IllegalStateException();
     }
@@ -433,7 +433,7 @@
   /**
    * Checks that bounds are correct.
    *
-   * @throw StringIndexOutOfBoundsException if the range is not legal
+   * @throws StringIndexOutOfBoundsException if the range is not legal
    */
   public static void checkStringBounds(int start, int end, int size) {
     if (start < 0) {