📰 Add visibility change triggers for bottom sheet content

chrome/android/java/src/org/chromium/chrome/browser/suggestions/SuggestionsBottomSheetContent.java

Index: chrome/android/java/src/org/chromium/chrome/browser/suggestions/SuggestionsBottomSheetContent.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/suggestions/SuggestionsBottomSheetContent.java b/chrome/android/java/src/org/chromium/chrome/browser/suggestions/SuggestionsBottomSheetContent.java
index 7640b438f4289e71c0cb2e6c0b57c96cc1c76160..59f794c67ee34af41e6badf6049dc2653567c9b0 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/suggestions/SuggestionsBottomSheetContent.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/suggestions/SuggestionsBottomSheetContent.java
@@ -12,6 +12,7 @@
 import android.view.View;
 
 import org.chromium.base.ApiCompatibilityUtils;
+import org.chromium.base.metrics.RecordUserAction;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.ChromeActivity;
 import org.chromium.chrome.browser.NativePageHost;
@@ -30,7 +31,7 @@
 import org.chromium.chrome.browser.widget.bottomsheet.BottomSheet;
 import org.chromium.chrome.browser.widget.bottomsheet.BottomSheetContentController;
 import org.chromium.chrome.browser.widget.bottomsheet.BottomSheetObserver;
-import org.chromium.chrome.browser.widget.bottomsheet.EmptyBottomSheetObserver;
+import org.chromium.chrome.browser.widget.bottomsheet.SheetContentStateChangeObserver;
 import org.chromium.chrome.browser.widget.displaystyle.UiConfig;
 
 /**
@@ -85,31 +86,45 @@ public void onDestroy() {
                 mContextMenuManager, mTileGroupDelegate);
         mRecyclerView.init(uiConfig, mContextMenuManager, adapter);
 
-        mBottomSheetObserver = new EmptyBottomSheetObserver() {
+        mBottomSheet = activity.getBottomSheet();
+        mBottomSheetObserver = new SheetContentStateChangeObserver(this, mBottomSheet) {
             @Override
-            public void onSheetOpened() {
+            public void onContentShown() {
+                SuggestionsMetrics.recordSurfaceVisible();
+                mSuggestionsUiDelegate.getEventReporter().onSurfaceOpened();
+
                 mRecyclerView.scrollToPosition(0);
 
                 adapter.refreshSuggestions();
-                mSuggestionsUiDelegate.getEventReporter().onSurfaceOpened();
-                SuggestionsMetrics.recordSurfaceVisible();
             }
 
             @Override
-            public void onSheetClosed() {
+            public void onContentHidden() {
                 SuggestionsMetrics.recordSurfaceHidden();
             }
 
+            @Override
+            public void onContentStateChanged(int sheetState) {
+                if (sheetState == BottomSheet.SHEET_STATE_HALF) {
+                    RecordUserAction.record("Suggestions.SurfaceHalfVisible");
+                } else if (sheetState == BottomSheet.SHEET_STATE_FULL) {
+                    RecordUserAction.record("Suggestions.SurfaceFullyVisible");
+                }
+            }
+
+            @Override
+            public void onSheetBackgrounded() {
+                onContentHidden();
+            }
+
+            @Override
+            public void onSheetForegrounded() {
+                SuggestionsMetrics.recordSurfaceVisible();
+                onContentStateChanged(getCurrentState());
+            }
         };
-        mBottomSheet = activity.getBottomSheet();
         mBottomSheet.addObserver(mBottomSheetObserver);
 
-        if (mBottomSheet.isSheetOpen()) {
-            adapter.refreshSuggestions();
-            mSuggestionsUiDelegate.getEventReporter().onSurfaceOpened();
-            SuggestionsMetrics.recordSurfaceVisible();
-        }
-
         mShadowView = (FadingShadowView) mView.findViewById(R.id.shadow);
         mShadowView.init(
                 ApiCompatibilityUtils.getColor(mView.getResources(), R.color.toolbar_shadow_color),