Add _embedder.yaml support to analyzer and analysis_server

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

Index: pkg/analyzer/lib/src/generated/engine.dart
diff --git a/pkg/analyzer/lib/src/generated/engine.dart b/pkg/analyzer/lib/src/generated/engine.dart
index 9eaeecc6913eacf3b4c1c4ae4365d0008b82c74d..17a62134b38715ad198607955cd60dc442508cf6 100644
--- a/pkg/analyzer/lib/src/generated/engine.dart
+++ b/pkg/analyzer/lib/src/generated/engine.dart
@@ -8,6 +8,7 @@ import 'dart:async';
 import 'dart:collection';
 import 'dart:math' as math;
 
+import 'package:analyzer/source/embedder.dart';
 import 'package:analyzer/src/cancelable_future.dart';
 import 'package:analyzer/src/context/cache.dart' as cache;
 import 'package:analyzer/src/context/context.dart' as newContext;
@@ -330,6 +331,9 @@ abstract class AnalysisContext {
    */
   void set analysisOptions(AnalysisOptions options);
 
+  /// Return the [EmbedderYamlLocator] for with this context.
+  EmbedderYamlLocator get embedderYamlLocator;

[pquitslund, 2015/11/12 17:43:09]

I'll defer to Brian as to whether we need this in the legacy `AnalysisContext`,
which is on the brink of disappearing.  Either way, I'd hope we could avoid this
leaking into API.  (That is keep it just in the impl.)

[Brian Wilkerson, 2015/11/13 19:54:18]

So to be clear, AnalysisContext is the public interface for analysis contexts,
and it won't be going away. (The class AnalysisContextImpl in this file will be
going away.)

But I agree, we don't want this in the public API.

It's kind of hard to search for uses in the code review tool, so I can't see
where this getter is being used, but the way we typically handle this is to add
an API like this to InternalAnalysisContext. Most of our code already uses that
interface rather than the public interface, so the getter would likely still be
available where you need it.

[Cutch, 2015/11/14 00:15:17]

Moved to InternalAnalysisContext.

+
   /**
    * Set the order in which sources will be analyzed by [performAnalysisTask] to
    * match the order of the sources in the given list of [sources]. If a source
@@ -964,6 +968,9 @@ class AnalysisContextImpl implements InternalAnalysisContext {
    */
   AnalysisOptionsImpl _options = new AnalysisOptionsImpl();
 
+  /// The embedder yaml locator for this context.
+  EmbedderYamlLocator _embedderYamlLocator = new EmbedderYamlLocator(null);
+
   /**
    * A flag indicating whether errors related to implicitly analyzed sources
    * should be generated and reported.
@@ -1156,6 +1163,9 @@ class AnalysisContextImpl implements InternalAnalysisContext {
   AnalysisOptions get analysisOptions => _options;
 
   @override
+  EmbedderYamlLocator get embedderYamlLocator => _embedderYamlLocator;
+  
+  @override
   void set analysisOptions(AnalysisOptions options) {
     bool needsRecompute = this._options.analyzeFunctionBodiesPredicate !=
             options.analyzeFunctionBodiesPredicate ||