[Suggestions] Separate init trigger from bottom sheet opening

We want the initialisation of the home sheet to happen when the bottom
sheet opens and shows the home sheet. However, even though it's the
default sheet, the bottom sheet can also open to show omnibox
suggestions. In that case the home sheet is not shown and should not
be loaded.

This CL makes initialisation happen the first time the sheet is shown
since the opening of the bottom sheet.

Making the home sheet not be selected when the omnibox suggestions are
shown is out of scope and tracked in https://crbug.com/731128

Bug: 735945
Change-Id: I61406ea0ff4207370d86d3fd0712e339813b7ff7
Reviewed-on: https://chromium-review.googlesource.com/563309Reviewed-by: Matthew Jones <mdjones@chromium.org>
Commit-Queue: Nicolas Dossou-Gbété <dgn@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488189}

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

@@ -93,25 +93,22 @@ public class SuggestionsBottomSheetContent implements BottomSheet.BottomSheetCon
 
         mBottomSheetObserver = new SuggestionsSheetVisibilityChangeObserver(this, activity) {
             @Override
-            public void onSheetOpened() {
-                mRecyclerView.setAdapter(adapter);
-
-                mRecyclerView.scrollToPosition(0);
-                adapter.refreshSuggestions();
-                mSuggestionsUiDelegate.getEventReporter().onSurfaceOpened();
-                mRecyclerView.getScrollEventReporter().reset();
-
-                if (ChromeFeatureList.isEnabled(
-                            ChromeFeatureList.CONTEXTUAL_SUGGESTIONS_CAROUSEL)
-                        && sheet.getActiveTab() != null) {
-                    updateContextualSuggestions(sheet.getActiveTab().getUrl());
+            public void onContentShown(boolean isFirstShown) {
+                if (isFirstShown) {
+                    mRecyclerView.setAdapter(adapter);
+
+                    mRecyclerView.scrollToPosition(0);
+                    adapter.refreshSuggestions();
+                    mSuggestionsUiDelegate.getEventReporter().onSurfaceOpened();
+                    mRecyclerView.getScrollEventReporter().reset();
+
+                    if (ChromeFeatureList.isEnabled(
+                                ChromeFeatureList.CONTEXTUAL_SUGGESTIONS_CAROUSEL)
+                            && sheet.getActiveTab() != null) {
+                        updateContextualSuggestions(sheet.getActiveTab().getUrl());
+                    }
                 }
 
-                super.onSheetOpened();
-            }
-
-            @Override
-            public void onContentShown() {
                 SuggestionsMetrics.recordSurfaceVisible();
             }
 

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

@@ -23,6 +23,7 @@ public abstract class SuggestionsSheetVisibilityChangeObserver
     @BottomSheet.SheetState
     private int mCurrentContentState;
     private boolean mCurrentVisibility;
+    private boolean mWasShownSinceLastOpen;
 
     private final ChromeActivity mActivity;
     private final BottomSheet.BottomSheetContent mContentObserved;
@@ -55,8 +56,11 @@ public abstract class SuggestionsSheetVisibilityChangeObserver
         mBottomSheet.removeObserver(this);
     }
 
-    /** Called when the observed sheet content becomes visible. */
-    public abstract void onContentShown();
+    /** Called when the observed sheet content becomes visible.
+     * @param isFirstShown Only {@code true} the first time suggestions are shown each time the
+     *                     sheet is opened.
+     */
+    public abstract void onContentShown(boolean isFirstShown);
 
     /** Called when the observed sheet content becomes invisible. */
     public abstract void onContentHidden();
@@ -72,6 +76,7 @@ public abstract class SuggestionsSheetVisibilityChangeObserver
     @Override
     @CallSuper
     public void onSheetOpened() {
+        mWasShownSinceLastOpen = false;
         onStateChange();
     }
 
@@ -109,7 +114,7 @@ public abstract class SuggestionsSheetVisibilityChangeObserver
     /**
      * Compares the current state of the bottom sheet and activity with the ones recorded at the
      * previous call and generates events based on the difference.
-     * @see #onContentShown()
+     * @see #onContentShown(boolean)
      * @see #onContentHidden()
      * @see #onContentStateChanged(int)
      */
@@ -132,7 +137,8 @@ public abstract class SuggestionsSheetVisibilityChangeObserver
 
         if (newVisibility != mCurrentVisibility) {
             if (newVisibility) {
-                onContentShown();
+                onContentShown(!mWasShownSinceLastOpen);
+                mWasShownSinceLastOpen = true;
             } else {
                 onContentHidden();
             }