ColorPicker: Add HC border to the color well and format toggler

Bug: 1012387
Change-Id: I9627134583db5f0b0c8390ccf4792b5287a5a0b4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1847869Reviewed-by: Mason Freed <masonfreed@chromium.org>
Reviewed-by: Kent Tamura <tkent@chromium.org>
Commit-Queue: Sanket Joshi <sajos@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#704452}

third_party/blink/renderer/core/html/forms/resources/color_picker.css

@@ -197,7 +197,13 @@ submission-button:hover {
     forced-color-adjust: none;
     border-color: WindowText;
   }
+  color-well {
+    border-bottom: 1px solid WindowText;
+  }
   color-selection-ring {
     forced-color-adjust: none;
   }
+  format-toggler {
+    border: 1px solid WindowText;
+  }
 }
\ No newline at end of file