Remove 'Enable' button on unsupported platforms. Added 'No hosts' message.

remoting/webapp/main.css

Index: remoting/webapp/main.css
diff --git a/remoting/webapp/main.css b/remoting/webapp/main.css
index f6cc0cc9198266c249576d9f1b567f58ad581032..fb4d1ddffd56cd42bcd362427118efbd847d6d9d 100644
--- a/remoting/webapp/main.css
+++ b/remoting/webapp/main.css
@@ -243,6 +243,7 @@ h2 {
   line-height:24px;
   font-weight: normal;
   color: #222;
+  margin-bottom: 10px;
 }
 
 section > h2 {
@@ -297,6 +298,21 @@ section {
   display: -webkit-box;
 }
 
+.host-list-empty-instructions {
+  padding-__MSG_@@bidi_start_edge__: 36px;
+  color: #666;
+  background-image: url('host_setup_instructions.png');
+  background-repeat: no-repeat;
+  background-position: -3px -2px;
+}
+
+#host-list-empty-hosting-supported {
+  margin-top: 14px;
+  padding-top: 20px;
+  border-top: 1px solid #E5E5E5;
+  background-position-y: 18px;
+}
+
 .selectable {
   -webkit-user-select: text;
   cursor: text;
@@ -371,11 +387,6 @@ section {
   min-width: 72px;
 }
 
-.host-list-table {
-  width: 100%;
-  border-spacing: 0;
-}
-
 td {
   vertical-align: middle;
 }
@@ -561,7 +572,7 @@ button {
 }
 
 #webapp-description {
-  margin: 10px 0;
+  margin-bottom: 10px;
 }
 
 #why-is-this-safe {