Devtools: Use Event.deepPath as a function if available.

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

Index: third_party/WebKit/Source/devtools/front_end/devtools.js
diff --git a/third_party/WebKit/Source/devtools/front_end/devtools.js b/third_party/WebKit/Source/devtools/front_end/devtools.js
index 05c2b25a3800a9cd76bba88af007f8f8a9264b7d..5eee11e3dcabdc684330eef79457bc6dc58a5cbb 100644
--- a/third_party/WebKit/Source/devtools/front_end/devtools.js
+++ b/third_party/WebKit/Source/devtools/front_end/devtools.js
@@ -908,6 +908,10 @@ function installBackwardsCompatibility()
     styleElement.type = "text/css";
     styleElement.textContent = "html /deep/ * { min-width: 0; min-height: 0; }";
     window.document.head.appendChild(styleElement);
+
+    // Support for legacy (<M49) frontends. Remove in M52.
+    if (Object.getOwnPropertyDescriptor(Event.prototype, "deepPath"))

[pfeldman, 2016/02/03 00:16:24]

Wouldn't it remove it at all times? I am not following this :)

[samli, 2016/02/03 00:17:57]

Yes. You want me to only remove it on attribute ones?

[pfeldman, 2016/02/04 00:19:58]

I was thinking of simply executing "Event.prototype.deepPath = undefined;"
unconditionally.

+        Event.prototype.deepPath = undefined;
 }
 
 function windowLoaded()