Revert "Report error if the same uri appears in multiple summaries."

pkg/analyzer/lib/src/summary/package_bundle_reader.dart

Index: pkg/analyzer/lib/src/summary/package_bundle_reader.dart
diff --git a/pkg/analyzer/lib/src/summary/package_bundle_reader.dart b/pkg/analyzer/lib/src/summary/package_bundle_reader.dart
index 1e443ede7d5842a2ed517e83f544fe0fce2d108a..616863fd8f94073679ec3fdd8c09cced3019aeb9 100644
--- a/pkg/analyzer/lib/src/summary/package_bundle_reader.dart
+++ b/pkg/analyzer/lib/src/summary/package_bundle_reader.dart
@@ -1,5 +1,4 @@
 import 'dart:io' as io;
-import 'dart:math' show min;
 
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/file_system/file_system.dart';
@@ -307,56 +306,6 @@ class StoreBasedSummaryResynthesizer extends SummaryResynthesizer {
 }
 
 /**
- * A [ConflictingSummaryException] indicates that two different summaries
- * provided to a [SummaryDataStore] conflict.
- */
-class ConflictingSummaryException implements Exception {
-  final String duplicatedUri;
-  final String summary1Uri;
-  final String summary2Uri;
-  String _message;
-
-  ConflictingSummaryException(Iterable<String> summaryPaths, this.duplicatedUri,
-      this.summary1Uri, this.summary2Uri) {
-    // Paths are often quite long.  Find and extract out a common prefix to
-    // build a more readable error message.
-    var prefix = _commonPrefix(summaryPaths.toList());
-    _message = '''
-These summaries conflict because they overlap:
-- ${summary1Uri.substring(prefix)}
-- ${summary2Uri.substring(prefix)}
-Both contain the file: ${duplicatedUri}.
-This typically indicates an invalid build rule where two or more targets
-include the same source.
-  ''';
-  }
-
-  /// Given a set of file paths, find a common prefix.
-  int _commonPrefix(List<String> strings) {
-    if (strings.isEmpty) return 0;
-    var first = strings.first;
-    int common = first.length;
-    for (int i = 1; i < strings.length; ++i) {
-      var current = strings[i];
-      common = min(common, current.length);
-      for (int j = 0; j < common; ++j) {
-        if (first[j] != current[j]) {
-          common = j;
-          if (common == 0) return 0;
-          break;
-        }
-      }
-    }
-    // The prefix should end with a file separator.
-    var last =
-        first.substring(0, common).lastIndexOf(io.Platform.pathSeparator);
-    return last < 0 ? 0 : last + 1;
-  }
-
-  String toString() => _message;
-}
-
-/**
  * A [SummaryDataStore] is a container for the data extracted from a set of
  * summary package bundles.  It contains maps which can be used to find linked
  * and unlinked summaries by URI.
@@ -393,11 +342,6 @@ class SummaryDataStore {
   final Map<String, String> uriToSummaryPath = <String, String>{};
 
   /**
-   * List of summary paths.
-   */
-  final Iterable<String> _summaryPaths;
-
-  /**
    * Create a [SummaryDataStore] and populate it with the summaries in
    * [summaryPaths].  If [recordDependencyInfo] is `true`, record
    * [PackageDependencyInfo] for each summary, for later access via
@@ -405,8 +349,7 @@ class SummaryDataStore {
    */
   SummaryDataStore(Iterable<String> summaryPaths,
       {bool recordDependencyInfo: false, ResourceProvider resourceProvider})
-      : _summaryPaths = summaryPaths,
-        dependencies =
+      : dependencies =
             recordDependencyInfo ? <PackageDependencyInfoBuilder>[] : null {
     summaryPaths.forEach((String path) => _fillMaps(path, resourceProvider));
   }
@@ -441,11 +384,6 @@ class SummaryDataStore {
     }
     for (int i = 0; i < bundle.unlinkedUnitUris.length; i++) {
       String uri = bundle.unlinkedUnitUris[i];
-      if (uriToSummaryPath.containsKey(uri) &&
-          (uriToSummaryPath[uri] != path)) {
-        throw new ConflictingSummaryException(
-            _summaryPaths, uri, uriToSummaryPath[uri], path);
-      }
       uriToSummaryPath[uri] = path;
       addUnlinkedUnit(uri, bundle.unlinkedUnits[i]);
     }