Add navigation controls to DevTools screencast view

Source/devtools/front_end/screencastView.css

Index: Source/devtools/front_end/screencastView.css
diff --git a/Source/devtools/front_end/screencastView.css b/Source/devtools/front_end/screencastView.css
index a9c1a8f9bab03c7f55de11dad8e2c366580bf6ff..47d649ea6157d9105da39eca28c5a29c5873691f 100644
--- a/Source/devtools/front_end/screencastView.css
+++ b/Source/devtools/front_end/screencastView.css
@@ -28,6 +28,29 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+.screencast-navigation {
+  -webkit-flex-direction: row;
+  display: -webkit-flex;
+}
+
+/* FIXME: replace unicode symbols with icons */
+.screencast-navigation button {
+  font-size: 125%;
+  font-weight: 900;
+}
+
+.screencast-navigation input {
+  -webkit-flex: 1;
+  border: 1px solid #ccc;
+  border-radius: 2px;
+  padding-left: 5px;
+}
+
+.screencast-navigation input:focus {
+  border: 1px solid #888;
+  outline: none;
+}
+
 .screencast-viewport {
     margin: 10px;
     border: 20px solid #333;