DevTools: Text-boxes borders are not seen on ColorPicker window.

Bug: 826231
Change-Id: I82f681337a754513a69d002042d42e1d5206efa5
TBR: dgozman
Reviewed-on: https://chromium-review.googlesource.com/993974Reviewed-by: Pavel Feldman <pfeldman@chromium.org>
Commit-Queue: Pavel Feldman <pfeldman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548233}

third_party/WebKit/Source/devtools/front_end/color_picker/spectrum.css

@@ -301,13 +301,12 @@
     width: 40px;
     overflow: hidden;
     text-align: center;
-    border: var(--divider-border);
-    border-radius: 2px;
     margin-right: 6px;
     line-height: 20px;
     padding: 0;
     color: #333;
     white-space: nowrap;
+    box-shadow: var(--focus-ring-inactive-shadow);
 }
 
 .spectrum-text-label {