Make "error" the default severity for checked mode compile time errors.

pkg/analyzer/lib/src/analyzer_impl.dart

Index: pkg/analyzer/lib/src/analyzer_impl.dart
diff --git a/pkg/analyzer/lib/src/analyzer_impl.dart b/pkg/analyzer/lib/src/analyzer_impl.dart
index 976f7b34048b2a8f5c90aa075274b605346f943b..79ef6b4936aabc6005e5e556fd6164cd508e63bc 100644
--- a/pkg/analyzer/lib/src/analyzer_impl.dart
+++ b/pkg/analyzer/lib/src/analyzer_impl.dart
@@ -36,14 +36,14 @@ DirectoryBasedDartSdk sdk;
 class AnalyzerImpl {
   /**
    * Compute the severity of the error; however, if
-   * [escalateCheckedModeCompileTimeErrors] is true, then escalate it to
-   * [ErrorSeverity.ERROR].
+   * [enableTypeChecks] is false, then de-escalate checked-mode compile time
+   * errors to a severity of [ErrorSeverity.INFO].
    */
   static ErrorSeverity computeSeverity(
-      AnalysisError error, bool escalateCheckedModeCompileTimeErrors) {
-    if (escalateCheckedModeCompileTimeErrors
+      AnalysisError error, bool enableTypeChecks) {
+    if (!enableTypeChecks
         && error.errorCode.type == ErrorType.CHECKED_MODE_COMPILE_TIME_ERROR) {
-      return ErrorSeverity.ERROR;
+      return ErrorSeverity.INFO;
     }
     return error.errorCode.errorSeverity;
   }