DevTools: teach SourceMapNamesResolver to resolve "this" object

third_party/WebKit/Source/devtools/front_end/platform/utilities.js

Index: third_party/WebKit/Source/devtools/front_end/platform/utilities.js
diff --git a/third_party/WebKit/Source/devtools/front_end/platform/utilities.js b/third_party/WebKit/Source/devtools/front_end/platform/utilities.js
index 6025a3629de647c7441b557256433e69e8e5fd31..23b353d1b0dd5d821ed0f62ce1165c3a141bd7bd 100644
--- a/third_party/WebKit/Source/devtools/front_end/platform/utilities.js
+++ b/third_party/WebKit/Source/devtools/front_end/platform/utilities.js
@@ -1281,6 +1281,19 @@ Map.prototype.keysArray = function()
 }
 
 /**
+ * @return {!Multimap<!KEY, !VALUE>}
+ */
+Map.prototype.inverse = function()
+{
+    var result = new Multimap();
+    for (var key of this.keys()) {
+        var value = this.get(key);
+        result.set(value, key);
+    }
+    return result;
+}
+
+/**
  * @constructor
  * @template K, V
  */