Fix to exclude patch files from search results (dartbug.com/5492).

compiler/java/com/google/dart/compiler/PackageLibraryManager.java

Index: compiler/java/com/google/dart/compiler/PackageLibraryManager.java
===================================================================
--- compiler/java/com/google/dart/compiler/PackageLibraryManager.java	(revision 12983)
+++ compiler/java/com/google/dart/compiler/PackageLibraryManager.java	(working copy)
@@ -329,6 +329,13 @@
   
   public Collection<SystemLibrary> getSystemLibraries(){
     return SDK_LIBRARY_MANAGER.getAllSystemLibraries();
+  }
+
+  /**
+   * Check if this URI denotes a patch file.
+   */
+  public static boolean isPatchFile(File file) {
+    return SDK_LIBRARY_MANAGER.isPatchFile(file.toURI());
   } 
   
 }