Gallery: Add toolbar at the top of window.

ui/file_manager/gallery/css/gallery.css

Index: ui/file_manager/gallery/css/gallery.css
diff --git a/ui/file_manager/gallery/css/gallery.css b/ui/file_manager/gallery/css/gallery.css
index cff180288b96318952a31f6a9974eaf9243b705f..b1ff62be0efc53643f8fa112d3c95ae97a93ffc9 100644
--- a/ui/file_manager/gallery/css/gallery.css
+++ b/ui/file_manager/gallery/css/gallery.css
@@ -183,11 +183,18 @@ input[type='checkbox']:checked {
 
 .gallery > .toolbar {
   border-top: 1px solid rgba(50, 50, 50, 0.8);
-  bottom: 0;
   height: 55px;
   overflow: hidden;
 }
 
+.gallery > .toolbar.top {
+  top: 45px; /* Header height. */
+}
+
+.gallery > .toolbar.bottom {
+  bottom: 0;
+}
+
 .gallery[tools]:not([slideshow]) > .header,
 .gallery[tools]:not([slideshow]) > .toolbar {
   opacity: 1;
@@ -288,12 +295,11 @@ input[type='checkbox']:checked {
 /* Filename */
 
 .gallery .filename-spacer {
-  flex: 0 1 auto;
+  flex: 1 0 auto;
   height: 100%;
   min-width: 140px;
   overflow: hidden;
   position: relative;
-  width: 252px;
 }
 
 .gallery .filename-spacer > * {
@@ -1149,13 +1155,13 @@ input[type='checkbox']:checked {
 
 /* Mosaic view. */
 .mosaic {
-  bottom: 55px;  /* Toolbar height. */
+  bottom: 0;
   left: 0;
   overflow-x: scroll;
   overflow-y: hidden;
   position: absolute;
   right: 0;
-  top: 0;
+  top: 100px; /* Header + Toolbar height. */
 
   /* transition-duration is set in Javascript. */
   transition-property: transform;