Use single InputPackagesResultProvider, without SdkSummaryResultProvider.

pkg/analyzer/lib/src/context/context.dart

Index: pkg/analyzer/lib/src/context/context.dart
diff --git a/pkg/analyzer/lib/src/context/context.dart b/pkg/analyzer/lib/src/context/context.dart
index 52a64b7fc47df3d2b1a8b85632b4658ff2c80400..5c20e0bf5d3c36f14502cf2fda5d90e79c48979d 100644
--- a/pkg/analyzer/lib/src/context/context.dart
+++ b/pkg/analyzer/lib/src/context/context.dart
@@ -204,6 +204,15 @@ class AnalysisContextImpl implements InternalAnalysisContext {
    */
   List<AnalysisListener> _listeners = new List<AnalysisListener>();
 
+  /**
+   * Determines whether this context should attempt to make use of the global
+   * SDK cache partition. Note that if this context is responsible for
+   * resynthesizing the SDK element model, this flag should be set to `false`,
+   * so that resynthesized elements belonging to this context won't leak into
+   * the global SDK cache partition.
+   */
+  bool useSdkCachePartition = true;
+
   @override
   ResultProvider resultProvider;
 
@@ -739,6 +748,9 @@ class AnalysisContextImpl implements InternalAnalysisContext {
       if (factory == null) {
         return new AnalysisCache(<CachePartition>[_privatePartition]);
       }
+      if (!useSdkCachePartition) {
+        return new AnalysisCache(<CachePartition>[_privatePartition]);
+      }
       DartSdk sdk = factory.dartSdk;
       if (sdk == null) {
         return new AnalysisCache(<CachePartition>[_privatePartition]);