Change to accommade Angular plugin and finalize removal of dependency to analysis_server

pkg/analyzer_plugin/lib/utilities/completion/completion_core.dart

Index: pkg/analyzer_plugin/lib/utilities/completion/completion_core.dart
diff --git a/pkg/analyzer_plugin/lib/utilities/completion/completion_core.dart b/pkg/analyzer_plugin/lib/utilities/completion/completion_core.dart
index edb3fe30e5b1cbc4050138c0e3a104f33dc679fe..eda05e45bf368b43d01f1f787e588c70c3b7c64b 100644
--- a/pkg/analyzer_plugin/lib/utilities/completion/completion_core.dart
+++ b/pkg/analyzer_plugin/lib/utilities/completion/completion_core.dart
@@ -46,6 +46,17 @@ abstract class CompletionCollector {
   void set offset(int offset);
 
   /**
+   * Indicates if the collector's offset has been set (and ultimately the
+   * length too).
+   */
+  bool get offsetIsSet;
+
+  /**
+   * Returns length of suggestions currently held.
+   */
+  int get suggestionsLength;
+
+  /**
    * Record the given completion [suggestion].
    */
   void addSuggestion(CompletionSuggestion suggestion);
@@ -104,6 +115,11 @@ class CompletionGenerator {
     } on AbortCompletion {
       return new GeneratorResult(null, notifications);
     }
+    if (collector.suggestions.isEmpty) {

[mfairhurst, 2017/06/13 20:31:39]

Should this instead check 'offsetIsSet'? And, what's the need for "no results"
to be equivalent to setting the completion offset and length to anything? Seems
reasonable, but also a bit strange.

[maxkim, 2017/06/13 20:49:21]

Ah that's right, I added this block before adding that variable. Somewhere in an
upper level, if the response has null offset/length, it crashes. Since that's
outside of the scope of where I'm comfortable contributing to, this is a
temporary yet effective bandaid.

+      collector
+        ..offset = request.offset
+        ..length = 0;
+    }
     CompletionGetSuggestionsResult result = new CompletionGetSuggestionsResult(
         collector.offset, collector.length, collector.suggestions);

[Brian Wilkerson, 2017/06/13 20:50:19]

I don't understand what the length of the suggestions has to do with anything
either. Perhaps we should just pass in `collector.offset ?? request.offset,
collector.length ?? 0`?

[maxkim, 2017/06/13 21:11:40]

This is following the assumption that if suggestions is empty, then it is
probable that length and offset hasn't been set. I will change it to ??=
assignments.

     return new GeneratorResult(result, notifications);