[Controls Refresh] Dark mode form - button: disabled state: text color appears too contrasty bugfix

This CL addresses an issue in which the disabled dark mode button control text color did not match the spec.

Bug: 1115749
Change-Id: I68f496b404443afda3042ad5ba10399f86fd4351
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2567615Reviewed-by: Kent Tamura <tkent@chromium.org>
Reviewed-by: Mason Freed <masonfreed@chromium.org>
Commit-Queue: Sam Sebree <sasebree@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#832672}

third_party/blink/renderer/core/html/resources/controls_refresh.css

@@ -80,7 +80,7 @@ input[type="file" i]:disabled::-webkit-file-upload-button,
 button:disabled {
   background-color: -internal-light-dark(rgba(239, 239, 239, 0.3), rgba(19, 1, 1, 0.3));
   border-color: -internal-light-dark(rgba(118, 118, 118, 0.3), rgba(195, 195, 195, 0.3));
-  color: -internal-light-dark(rgba(16, 16, 16, 0.3), white);
+  color: -internal-light-dark(rgba(16, 16, 16, 0.3), rgba(255, 255, 255, 0.3));
 }
 
 input[type="password" i]::-internal-reveal {