DevTools: CharacterIdMap should be able to return empty string

third_party/WebKit/Source/devtools/front_end/common/CharacterIdMap.js

Index: third_party/WebKit/Source/devtools/front_end/common/CharacterIdMap.js
diff --git a/third_party/WebKit/Source/devtools/front_end/common/CharacterIdMap.js b/third_party/WebKit/Source/devtools/front_end/common/CharacterIdMap.js
index dedb0b051a90d897c7ec151e20efb9ba0ae01418..794218d3afa1ad166da7ae4cb8203e398c742440 100644
--- a/third_party/WebKit/Source/devtools/front_end/common/CharacterIdMap.js
+++ b/third_party/WebKit/Source/devtools/front_end/common/CharacterIdMap.js
@@ -35,6 +35,9 @@ Common.CharacterIdMap = class {
    * @return {?T}
    */
   fromChar(character) {
-    return this._characterToElement.get(character) || null;
+    var object = this._characterToElement.get(character);
+    if (object === undefined)
+      return null;
+    return object;
   }
 };