Reduce usage of webkit prefixes in extension examples

chrome/common/extensions/docs/examples/api/browsingData/basic/popup.css

Index: chrome/common/extensions/docs/examples/api/browsingData/basic/popup.css
diff --git a/chrome/common/extensions/docs/examples/api/browsingData/basic/popup.css b/chrome/common/extensions/docs/examples/api/browsingData/basic/popup.css
index 372376d30f61846a7dff6a739d78d5dd3b272f08..52b1af4f74fd51bb35d683fcb5d7cb86e79a075b 100644
--- a/chrome/common/extensions/docs/examples/api/browsingData/basic/popup.css
+++ b/chrome/common/extensions/docs/examples/api/browsingData/basic/popup.css
@@ -25,8 +25,8 @@ label {
 }
 
 form {
+  transition: transform 0.25s ease;
   width: 563px;
-  -webkit-transition: -webkit-transform 0.25s ease;
 }
 
 button {
@@ -58,8 +58,8 @@ button {
   border-radius: 5px;
   color: #FFF;
   font: 1.5em/1.2 Helvetica Neue, sans-serif;
-  -webkit-transition: all 1.0s ease;
-  -webkit-transform: scale(0);
+  transition: all 1.0s ease;
+  transform: scale(0);
 }
 
 .overlay a {
@@ -68,5 +68,5 @@ button {
 
 .overlay.visible {
   opacity: 1;
-  -webkit-transform: scale(1);
+  transform: scale(1);
 }