Convert Chromoting to use the new, non-deprecated flexbox

This is basically a search and replace for -webkit-box -> -webkit-flex,
and some related properties.

I have tested that the UI still looks correct, although I couldn't find
out where connection-history-options is used.

R=jamiewalch@chromium.org
BUG=


Review URL: https://chromiumcodereview.appspot.com/12847005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@192972 0039d316-1c4b-4281-b951-d872f2087c98

remoting/webapp/connection_history.css

@@ -11,7 +11,7 @@
 
 #connection-history-options {
   margin-top: 30px;
-  display: -webkit-box;
+  display: -webkit-flex;
 }
 
 #connection-history-scroller {

remoting/webapp/main.css

@@ -247,7 +247,7 @@ section > h2 {
 }
 
 header {
-  display: -webkit-box;
+  display: -webkit-flex;
   width: 100%;
 }
 
@@ -279,7 +279,7 @@ section {
 }
 
 .box-spacer {
-  -webkit-box-flex: 1;
+  -webkit-flex: 1;
 }
 
 .centered {
@@ -291,7 +291,7 @@ section {
 }
 
 .box {
-  display: -webkit-box;
+  display: -webkit-flex;
 }
 
 .host-list-empty-instructions {
@@ -315,8 +315,8 @@ section {
 }
 
 .section-row {
-  display: -webkit-box;
-  -webkit-box-align: center;
+  display: -webkit-flex;
+  -webkit-align-items: center;
   padding: 10px 0;
   border-top: 1px solid #EBEBEB;
 }
@@ -573,7 +573,7 @@ button {
   top: 200px;
   left: 0;
   width: 100%;
-  display: -webkit-box;
+  display: -webkit-flex;
 }
 
 .dialog-screen {

remoting/webapp/toolbar.css

@@ -44,7 +44,7 @@
   background-color: #e9e9e9;
   box-shadow: 0px 0px 10px rgba(0, 0, 0, 0.5);
   pointer-events: all;
-  display: -webkit-box;
+  display: -webkit-flex;
 }
 
 .toolbar-border > div {