Remove vendor specific CSS prefixes.

chrome/browser/resources/about_memory_mac.html

Index: chrome/browser/resources/about_memory_mac.html
diff --git a/chrome/browser/resources/about_memory_mac.html b/chrome/browser/resources/about_memory_mac.html
index 9b6d223d2fd6831036f96c3129e32be543c714b0..ebdfd123191698a270606b2de71a7e0dba57c08b 100644
--- a/chrome/browser/resources/about_memory_mac.html
+++ b/chrome/browser/resources/about_memory_mac.html
@@ -59,9 +59,9 @@ div#header {
   position: relative;
   overflow: hidden;
   background: #5296de;
-  -webkit-background-size: 100%;
+  background-size: 100%;
   border: 1px solid #3a75bd;
-  -webkit-border-radius: 6px;
+  border-radius: 6px;
   color: white;
   text-shadow: 0 0 2px black;
 }
@@ -129,7 +129,7 @@ div.viewOptions input {
   font-family: Helvetica, sans-serif;
   font-size: 100%;
   border: 1px solid #b5b5b5;
-  -webkit-border-radius: 6px;
+  border-radius: 6px;
   padding: 0.3em 0.4em;
 }
 div.viewOptions input:focus {
@@ -305,7 +305,7 @@ div.help div {
   max-width: 30em;
   -webkit-box-shadow: 3px 3px 4px rgba(0, 0, 0, 0.33);
   border: 1px solid #a8cfff;
-  -webkit-border-radius: 0;
+  border-radius: 0;
   line-height: 140%;
   font-size: 92%;
 }