Fix search box alignment issue

Changes:
Change the spacing between icon and textfield from 12 to 16 when search
box is opened to align query with search results.

Bug: 844182
Change-Id: Ie0715fd758226010342410179e1fbc0a1224856b
Reviewed-on: https://chromium-review.googlesource.com/c/1327536Reviewed-by: Michael Wasserman <msw@chromium.org>
Commit-Queue: Weidong Guo <weidongg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606714}

ash/app_list/views/search_box_view.cc

@@ -288,12 +288,12 @@ void SearchBoxView::UpdateBackground(double progress,
 void SearchBoxView::UpdateLayout(double progress,
                                  ash::AppListState current_state,
                                  ash::AppListState target_state) {
+  const int horizontal_spacing = gfx::Tween::LinearIntValueBetween(
+      progress, GetBoxLayoutPaddingForState(current_state),
+      GetBoxLayoutPaddingForState(target_state));
   box_layout()->set_inside_border_insets(
-      gfx::Insets(0,
-                  gfx::Tween::LinearIntValueBetween(
-                      progress, GetBoxLayoutPaddingForState(current_state),
-                      GetBoxLayoutPaddingForState(target_state)),
-                  0, 0));
+      gfx::Insets(0, horizontal_spacing, 0, 0));
+  box_layout()->set_between_child_spacing(horizontal_spacing);
   if (show_assistant_button()) {
     assistant_button()->layer()->SetOpacity(gfx::Tween::LinearIntValueBetween(
         progress, GetAssistantButtonOpacityForState(current_state),

ui/views/layout/box_layout.h

@@ -15,7 +15,7 @@
 namespace gfx {
 class Rect;
 class Size;
-}
+}  // namespace gfx
 
 namespace views {
 
@@ -129,6 +129,10 @@ class VIEWS_EXPORT BoxLayout : public LayoutManager {
     minimum_cross_axis_size_ = size;
   }
 
+  void set_between_child_spacing(int spacing) {
+    between_child_spacing_ = spacing;
+  }
+
   // Sets the flex weight for the given |view|. Using the preferred size as
   // the basis, free space along the main axis is distributed to views in the
   // ratio of their flex weights. Similarly, if the views will overflow the
@@ -307,7 +311,7 @@ class VIEWS_EXPORT BoxLayout : public LayoutManager {
   gfx::Insets inside_border_insets_;
 
   // Spacing to put in between child views.
-  const int between_child_spacing_;
+  int between_child_spacing_;
 
   // The alignment of children in the main axis. This is
   // MAIN_AXIS_ALIGNMENT_START by default.
@@ -335,6 +339,6 @@ class VIEWS_EXPORT BoxLayout : public LayoutManager {
   DISALLOW_IMPLICIT_CONSTRUCTORS(BoxLayout);
 };
 
-} // namespace views
+}  // namespace views
 
 #endif  // UI_VIEWS_LAYOUT_BOX_LAYOUT_H_