Replace and remove JavaException(s).

pkg/analyzer/lib/src/generated/source.dart

Index: pkg/analyzer/lib/src/generated/source.dart
diff --git a/pkg/analyzer/lib/src/generated/source.dart b/pkg/analyzer/lib/src/generated/source.dart
index 264a5db4b90dd1b76990774977612a1f85e62b60..41f6c8846edcb885d3cb4f8ee861b5ce60e31102 100644
--- a/pkg/analyzer/lib/src/generated/source.dart
+++ b/pkg/analyzer/lib/src/generated/source.dart
@@ -212,9 +212,9 @@ class LineInfo {
    */
   LineInfo._(this.lineStarts) {
     if (lineStarts == null) {
-      throw new IllegalArgumentException("lineStarts must be non-null");
+      throw new ArgumentError("lineStarts must be non-null");
     } else if (lineStarts.length < 1) {
-      throw new IllegalArgumentException("lineStarts must be non-empty");
+      throw new ArgumentError("lineStarts must be non-empty");
     }
   }
 
@@ -379,7 +379,7 @@ class NonExistingSource extends Source {
 
   @override
   TimestampedData<String> get contents {
-    throw new UnsupportedOperationException('$fullName does not exist.');
+    throw new UnsupportedError('$fullName does not exist.');
   }
 
   @override