Rework requests in execution domain

pkg/analysis_server/test/integration/integration_test_methods.dart

Index: pkg/analysis_server/test/integration/integration_test_methods.dart
diff --git a/pkg/analysis_server/test/integration/integration_test_methods.dart b/pkg/analysis_server/test/integration/integration_test_methods.dart
index 4850c836d5d03cec0c4506399548349e72c28ec7..36f00ab265c721b8d45a7916dc216cbe0bc6c3fb 100644
--- a/pkg/analysis_server/test/integration/integration_test_methods.dart
+++ b/pkg/analysis_server/test/integration/integration_test_methods.dart
@@ -1325,7 +1325,8 @@ abstract class IntegrationTestMixin {
    *
    * contextRoot ( FilePath )
    *
-   *   The path of the Dart or HTML file that will be launched.
+   *   The path of the Dart or HTML file that will be launched, or the path of
+   *   the directory containing the file.
    *
    * Returns
    *
@@ -1366,22 +1367,22 @@ abstract class IntegrationTestMixin {
    * Map a URI from the execution context to the file that it corresponds to,
    * or map a file to the URI that it corresponds to in the execution context.
    *
-   * Exactly one of the file and uri fields must be provided.
+   * Exactly one of the file and uri fields must be provided. If both fields
+   * are provided, then an error of type INVALID_PARAMETER will be generated.
+   * Similarly, if neither field is provided, then an error of type
+   * INVALID_PARAMETER will be generated.
    *
    * If the file field is provided and the value is not the path of a file
    * (either the file does not exist or the path references something other
-   * than a file), then an error of type MAP_URI_INVALID_FILE will be
-   * generated.
+   * than a file), then an error of type INVALID_PARAMETER will be generated.
    *
    * If the uri field is provided and the value is not a valid URI or if the
    * URI references something that is not a file (either a file that does not
    * exist or something other than a file), then an error of type
-   * MAP_URI_INVALID_URI will be generated.
+   * INVALID_PARAMETER will be generated.
    *
-   * If the contextRoot used to create the execution context is not a file
-   * (either the file does not exist or the path references something other
-   * than a file), then an error of type INVALID_EXECUTION_CONTEXT will be
-   * generated.
+   * If the contextRoot used to create the execution context does not exist,
+   * then an error of type INVALID_EXECUTION_CONTEXT will be generated.
    *
    * Parameters
    *