DevTools: Autocomplete class names in ClassesPaneWidget

third_party/WebKit/Source/devtools/front_end/elements/elementsPanel.css

Index: third_party/WebKit/Source/devtools/front_end/elements/elementsPanel.css
diff --git a/third_party/WebKit/Source/devtools/front_end/elements/elementsPanel.css b/third_party/WebKit/Source/devtools/front_end/elements/elementsPanel.css
index 34751a80a48bfdd3e469aec7e87481f92fe4c020..e0b19874a8d7184e24499d67d4d661a640a76d86 100644
--- a/third_party/WebKit/Source/devtools/front_end/elements/elementsPanel.css
+++ b/third_party/WebKit/Source/devtools/front_end/elements/elementsPanel.css
@@ -494,6 +494,14 @@
     line-height: 15px;
     margin-left: 3px;
     width: calc(100% - 7px);
+    -webkit-user-modify: read-write-plaintext-only;
+    background-color: #fff;
+    cursor: text;
+}
+
+.styles-element-classes-pane .new-class-input:empty:before {
+    content: attr(placeholder);
+    color: darkgray;
 }
 
 .styles-element-state-pane > div {