DevTools: Add keyboard focus highlight when focusing window

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

Index: third_party/WebKit/Source/devtools/front_end/ui/UIUtils.js
diff --git a/third_party/WebKit/Source/devtools/front_end/ui/UIUtils.js b/third_party/WebKit/Source/devtools/front_end/ui/UIUtils.js
index 13125efcf06748cf6851afa7b85e67f57636e3ac..d8b5ded911a07a2fd5aaed0aca41d4783bcde53b 100644
--- a/third_party/WebKit/Source/devtools/front_end/ui/UIUtils.js
+++ b/third_party/WebKit/Source/devtools/front_end/ui/UIUtils.js
@@ -711,6 +711,19 @@ UI.createShadowRootWithCoreStyles = function(element, cssFile) {
 UI._windowFocused = function(document, event) {
   if (event.target.document.nodeType === Node.DOCUMENT_NODE)
     document.body.classList.remove('inactive');
+  UI._keyboardFocus = true;
+  var listener = () => {
+    var activeElement = document.deepActiveElement();
+    if (activeElement)
+      activeElement.removeAttribute('data-keyboard-focus');
+    UI._keyboardFocus = false;
+  };
+  document.defaultView.requestAnimationFrame(() => {
+    UI._keyboardFocus = false;
+    document.removeEventListener('mousedown', listener, true);
+  });
+  document.addEventListener('mousedown', listener, true);
+
 };
 
 /**