[Instant Start] Add Feed placeholder header with menu.

Bug: 1076139
Change-Id: Iceed665287c5bf438b240a53e6379704e15edc59
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2293217
Commit-Queue: Hao Dong <spdonghao@chromium.org>
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Reviewed-by: Xi Han <hanxi@chromium.org>
Reviewed-by: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#790870}

chrome/android/features/start_surface/internal/java/res/layout/feed_loading_layout.xml

@@ -8,29 +8,10 @@
     android:orientation="vertical">
 
     <LinearLayout
+        android:id="@+id/feed_placeholder_header"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:gravity="center_vertical"
-        android:minHeight="@dimen/snippets_article_header_height"
-        android:orientation="horizontal"
-        android:paddingTop="8dp"
-        android:paddingBottom="8dp">
-
-        <TextView
-            android:id="@+id/header_title"
-            android:layout_width="0dp"
-            android:layout_height="wrap_content"
-            android:layout_weight="1"
-            android:paddingStart="6dp"
-            android:textAlignment="viewStart"
-            android:textAppearance="@style/TextAppearance.TextMediumThick.Primary" />
-
-        <TextView
-            android:id="@+id/header_status"
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:textAppearance="@style/TextAppearance.TextMedium.Blue" />
-    </LinearLayout>
+        android:orientation="vertical"/>
 
     <LinearLayout
         android:id="@+id/placeholders_layout"

chrome/android/features/start_surface/internal/java/src/org/chromium/chrome/features/start_surface/FeedLoadingLayout.java

@@ -4,6 +4,7 @@
 
 package org.chromium.chrome.features.start_surface;
 
+import android.annotation.SuppressLint;
 import android.content.Context;
 import android.content.res.Configuration;
 import android.content.res.Resources;
@@ -12,10 +13,14 @@ import android.graphics.drawable.LayerDrawable;
 import android.os.SystemClock;
 import android.util.AttributeSet;
 import android.util.TypedValue;
+import android.view.LayoutInflater;
+import android.view.View;
 import android.view.ViewGroup;
 import android.widget.ImageView;
 import android.widget.LinearLayout;
 
+import org.chromium.chrome.browser.flags.CachedFeatureFlags;
+import org.chromium.chrome.browser.flags.ChromeFeatureList;
 import org.chromium.chrome.start_surface.R;
 import org.chromium.components.browser_ui.widget.displaystyle.HorizontalDisplayStyle;
 import org.chromium.components.browser_ui.widget.displaystyle.UiConfig;
@@ -50,7 +55,7 @@ public class FeedLoadingLayout extends LinearLayout {
     @Override
     protected void onFinishInflate() {
         super.onFinishInflate();
-        // TODO (crbug.com/1079443): Inflate article suggestions section header here.
+        setHeader();
         setPlaceholders();
         mLayoutInflationCompleteMs = SystemClock.elapsedRealtime();
     }
@@ -61,6 +66,29 @@ public class FeedLoadingLayout extends LinearLayout {
         setPlaceholders();
     }
 
+    /**
+     * Set the header blank for the placeholder.The header blank should be consistent with the
+     * sectionHeaderView of {@link ExploreSurfaceCoordinator.FeedSurfaceCreator#}
+     */
+    @SuppressLint("InflateParams")
+    private void setHeader() {
+        LayoutInflater inflater = LayoutInflater.from(mContext);
+        View header;
+        // This flag is checked directly with ChromeFeatureList#isEnabled() in other places. Using
+        // CachedFeatureFlags#isEnabled here is deliberate for a pre-native check. This
+        // inconsistency is fine because the check here is for the Feed header blank size, the
+        // mismatch is bearable and only once for every change.
+        if (CachedFeatureFlags.isEnabled(ChromeFeatureList.REPORT_FEED_USER_ACTIONS)) {
+            header = inflater.inflate(
+                    R.layout.new_tab_page_snippets_expandable_header_with_menu, null, false);
+            header.findViewById(R.id.header_menu).setVisibility(INVISIBLE);
+        } else {
+            header = inflater.inflate(R.layout.ss_feed_header, null, false);
+        }
+        LinearLayout headerView = findViewById(R.id.feed_placeholder_header);
+        headerView.addView(header);
+    }
+
     private void setPlaceholders() {
         setPadding();
         boolean isLandscape = getResources().getConfiguration().orientation

chrome/android/java/src/org/chromium/chrome/browser/app/flags/ChromeCachedFlags.java

@@ -65,6 +65,7 @@ public class ChromeCachedFlags {
                 ChromeFeatureList.PAINT_PREVIEW_DEMO,
                 ChromeFeatureList.PAINT_PREVIEW_SHOW_ON_STARTUP,
                 ChromeFeatureList.PRIORITIZE_BOOTSTRAP_TASKS,
+                ChromeFeatureList.REPORT_FEED_USER_ACTIONS,
                 ChromeFeatureList.START_SURFACE_ANDROID,
                 ChromeFeatureList.SWAP_PIXEL_FORMAT_TO_FIX_CONVERT_FROM_TRANSLUCENT,
                 ChromeFeatureList.TAB_GRID_LAYOUT_ANDROID,

chrome/browser/flags/android/java/src/org/chromium/chrome/browser/flags/CachedFeatureFlags.java

@@ -76,6 +76,7 @@ public class CachedFeatureFlags {
             put(ChromeFeatureList.OMNIBOX_SUGGESTIONS_RECYCLER_VIEW, false);
             put(ChromeFeatureList.TEST_DEFAULT_DISABLED, false);
             put(ChromeFeatureList.TEST_DEFAULT_ENABLED, true);
+            put(ChromeFeatureList.REPORT_FEED_USER_ACTIONS, false);
         }
     };