Release thumbnail when TabGridView is recycled

This depends on https://crrev.com/c/1595292 to actually release the
memory of the Bitmap.

On Pixel 2 XL, before this CL, there can be up to 8 (visible or
to-be-visible cards) + 5 (recycled in the view pool) thumbnail Bitmaps
in the memory after GC when GTS is visible. After hiding GTS, there are
still 5 Bitmaps in the recycled views after GC. This CL addresses the
recycled views in the pool.

Bug: 959054
Change-Id: I601417e5d2e67eafd69aee36fe00614beb046aff
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1595128
Commit-Queue: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Reviewed-by: Yusuf Ozuysal <yusufo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#661105}

chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_management/TabGridViewBinder.java

@@ -76,8 +76,7 @@ class TabGridViewBinder {
             if (fetcher == null) return;
             Callback<Bitmap> callback = result -> {
                 if (result == null) {
-                    holder.thumbnail.setImageResource(0);
-                    holder.thumbnail.setMinimumHeight(holder.thumbnail.getWidth());
+                    holder.resetThumbnail();
                 } else {
                     holder.thumbnail.setImageBitmap(result);
                 }

chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_management/TabGridViewHolder.java

@@ -71,4 +71,9 @@ class TabGridViewHolder extends RecyclerView.ViewHolder {
     public int getTabId() {
         return mTabId;
     }
+
+    public void resetThumbnail() {
+        thumbnail.setImageResource(0);
+        thumbnail.setMinimumHeight(thumbnail.getWidth());
+    }
 }

chrome/android/features/tab_ui/java/src/org/chromium/chrome/browser/tasks/tab_management/TabListCoordinator.java

@@ -83,8 +83,13 @@ public class TabListCoordinator implements Destroyable {
         RecyclerViewAdapter adapter;
         if (mMode == TabListMode.GRID) {
             SimpleRecyclerViewMcpBase<PropertyModel, TabGridViewHolder, PropertyKey> mcp =
-                    new SimpleRecyclerViewMcpBase<>(
-                            null, TabGridViewBinder::onBindViewHolder, tabListModel);
+                    new SimpleRecyclerViewMcpBase<PropertyModel, TabGridViewHolder, PropertyKey>(
+                            null, TabGridViewBinder::onBindViewHolder, tabListModel) {
+                        @Override
+                        public void onViewRecycled(TabGridViewHolder viewHolder) {
+                            viewHolder.resetThumbnail();
+                        }
+                    };
             adapter = new RecyclerViewAdapter<>(mcp, TabGridViewHolder::create);
             mModelChangeProcessor = mcp;
         } else if (mMode == TabListMode.STRIP) {