More options file validation (and API iteration).

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

Index: pkg/analyzer/lib/src/generated/error.dart
diff --git a/pkg/analyzer/lib/src/generated/error.dart b/pkg/analyzer/lib/src/generated/error.dart
index eac324c8dd64f251c560a84c8d3629437ca61241..af45572c7bba909c839ffd665d84963d9bba4654 100644
--- a/pkg/analyzer/lib/src/generated/error.dart
+++ b/pkg/analyzer/lib/src/generated/error.dart
@@ -296,7 +296,10 @@ class AnalysisErrorWithProperties extends AnalysisError {
 }
 
 /**
- * The error codes used for errors in analysis options files.
+ * The error codes used for errors in analysis options files. The convention for
+ * this class is for the name of the error code to indicate the problem that
+ * caused the error to be generated and for the error message to explain what is
+ * wrong and, when appropriate, how the problem can be corrected.
  */
 class AnalysisOptionsErrorCode extends ErrorCode {
   /**
@@ -323,7 +326,10 @@ class AnalysisOptionsErrorCode extends ErrorCode {
 }
 
 /**
- * The error codes used for warnings in analysis options files.
+ * The error codes used for warnings in analysis options files. The convention
+ * for this class is for the name of the error code to indicate the problem that
+ * caused the error to be generated and for the error message to explain what is
+ * wrong and, when appropriate, how the problem can be corrected.
  */
 class AnalysisOptionsWarningCode extends ErrorCode {
   /**