Clean up PaymentRequest integration tests.

chrome/test/data/android/payments/style.css

Index: chrome/test/data/android/payments/style.css
diff --git a/third_party/WebKit/Source/devtools/front_end/resources/appManifestView.css b/chrome/test/data/android/payments/style.css
similarity index 66%
copy from third_party/WebKit/Source/devtools/front_end/resources/appManifestView.css
copy to chrome/test/data/android/payments/style.css
index d9dcd7325975a4ff1b3e3fa85c56c72422126e53..1390298b8a6f76f7431d79a4e1d465c7a61f37b9 100644
--- a/third_party/WebKit/Source/devtools/front_end/resources/appManifestView.css
+++ b/chrome/test/data/android/payments/style.css
@@ -3,3 +3,13 @@
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
+
+button {
+  width: 100%;
+  height: 5em;
+  font-size: 3em;
+}
+
+pre {
+  font-size: 2em;
+}