java2dart improvement - use field if getter/setter are trivial.

pkg/analyzer_experimental/lib/src/generated/instrumentation.dart

Index: pkg/analyzer_experimental/lib/src/generated/instrumentation.dart
diff --git a/pkg/analyzer_experimental/lib/src/generated/instrumentation.dart b/pkg/analyzer_experimental/lib/src/generated/instrumentation.dart
index 7d059c5d14b0a15bc37a7c385cff6ed1fbec22a5..d297da4f257b94762b1e4ee60ce615da0b670a6e 100644
--- a/pkg/analyzer_experimental/lib/src/generated/instrumentation.dart
+++ b/pkg/analyzer_experimental/lib/src/generated/instrumentation.dart
@@ -38,7 +38,7 @@ class Instrumentation {
   /**
    * A builder that will silently ignore all data and logging requests.
    */
-  static InstrumentationBuilder _NULL_INSTRUMENTATION_BUILDER = new InstrumentationBuilder_16();
+  static final InstrumentationBuilder nullBuilder = new InstrumentationBuilder_16();
 
   /**
    * An instrumentation logger that can be used when no other instrumentation logger has been
@@ -73,13 +73,6 @@ class Instrumentation {
   static InstrumentationLogger get logger => _CURRENT_LOGGER;
 
   /**
-   * Return a builder that will silently ignore all data and logging requests.
-   *
-   * @return the builder (not `null`)
-   */
-  static InstrumentationBuilder get nullBuilder => _NULL_INSTRUMENTATION_BUILDER;
-
-  /**
    * Is this instrumentation system currently configured to drop instrumentation data provided to
    * it?
    *
@@ -113,7 +106,7 @@ class InstrumentationBuilder_16 implements InstrumentationBuilder {
   InstrumentationBuilder record(Exception exception) => this;
 }
 class InstrumentationLogger_17 implements InstrumentationLogger {
-  InstrumentationBuilder createBuilder(String name) => Instrumentation._NULL_INSTRUMENTATION_BUILDER;
+  InstrumentationBuilder createBuilder(String name) => Instrumentation.nullBuilder;
 }
 /**
  * The interface `InstrumentationBuilder` defines the behavior of objects used to collect data