In Search Result Tile View, Center Rating & Star when there is no price.

This can happen for reinstall candidates, but not for typical play
store candidates. UX from Shibasheikh@ .

Screenshots of before/after:

https://photos.app.goo.gl/sgnKe5pSYTX9AT5P9

Bug: 911427
Change-Id: Ia32be4956f734410b20e8102e755293f4d1b023e
Reviewed-on: https://chromium-review.googlesource.com/c/1469801Reviewed-by: Jenny Zhang <jennyz@chromium.org>
Commit-Queue: Rob Schonberger <robsc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#634736}

ash/app_list/views/search_result_tile_item_view.cc

@@ -57,6 +57,13 @@ constexpr int kIconSelectedCornerRadius = 4;
 // Icon selected color, Google Grey 900 8%.
 constexpr int kIconSelectedColor = SkColorSetA(gfx::kGoogleGrey900, 0x14);
 
+// Offset for centering star rating when there is no price.
+constexpr int kSearchRatingCenteringOffset =
+    ((kSearchTileWidth -
+      (kSearchRatingSize + kSearchRatingStarHorizontalSpacing +
+       kSearchRatingStarSize)) /
+     2);
+
 constexpr SkColor kSearchTitleColor = gfx::kGoogleGrey900;
 constexpr SkColor kSearchAppRatingColor = gfx::kGoogleGrey700;
 constexpr SkColor kSearchAppPriceColor = gfx::kGoogleGreen600;
@@ -526,9 +533,16 @@ void SearchResultTileItemView::Layout() {
     rect.set_height(title_->GetPreferredSize().height());
     title_->SetBoundsRect(rect);
 
+    // If there is no price set, we center the rating.
+    const bool center_rating =
+        rating_ && rating_star_ && price_ && price_->text().empty();
+    const int rating_horizontal_offset =
+        center_rating ? kSearchRatingCenteringOffset : 0;
+
     if (rating_) {
       gfx::Rect rating_rect(rect);
-      rating_rect.Inset(0, title_->GetPreferredSize().height(), 0, 0);
+      rating_rect.Inset(rating_horizontal_offset,
+                        title_->GetPreferredSize().height(), 0, 0);
       rating_rect.set_size(rating_->GetPreferredSize());
       rating_rect.set_width(kSearchRatingSize);
       rating_->SetBoundsRect(rating_rect);
@@ -536,11 +550,11 @@ void SearchResultTileItemView::Layout() {
 
     if (rating_star_) {
       gfx::Rect rating_star_rect(rect);
-      rating_star_rect.Inset(
-          kSearchRatingSize + kSearchRatingStarHorizontalSpacing,
-          title_->GetPreferredSize().height() +
-              kSearchRatingStarVerticalSpacing,
-          0, 0);
+      rating_star_rect.Inset(rating_horizontal_offset + kSearchRatingSize +
+                                 kSearchRatingStarHorizontalSpacing,
+                             title_->GetPreferredSize().height() +
+                                 kSearchRatingStarVerticalSpacing,
+                             0, 0);
       rating_star_rect.set_size(rating_star_->GetPreferredSize());
       rating_star_->SetBoundsRect(rating_star_rect);
     }