chrome/android: Fixed bug in highlighting data saver menu footer

The data saver menu footer is supposed to be highlighted when the data
saver in-product help is shown but it is not. This patch fixed it by
changing the ID that is highlighted to be the inflatedID of the app menu footer
view stub.

BUG=747486

Change-Id: Iaf43badcf277dd424fc02fbafa4d27e51c03737c
Reviewed-on: https://chromium-review.googlesource.com/581879Reviewed-by: Tommy Nyquist <nyquist@chromium.org>
Commit-Queue: Angela Shao <angelashao@google.com>
Cr-Commit-Position: refs/heads/master@{#488785}

chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java

@@ -1559,18 +1559,18 @@ public class Tab
         // Don't show data saver footer if Chrome Home is enabled (temporary fix for M61)
         if (FeatureUtilities.isChromeHomeEnabled()) return;
 
-        if (!tracker.shouldTriggerHelpUI(FeatureConstants.DATA_SAVER_DETAIL_FEATURE)) return;
-
-        showDataSaverInProductHelp(tracker);
+        maybeShowDataSaverInProductHelp(tracker);
     }
 
-    private void showDataSaverInProductHelp(final FeatureEngagementTracker tracker) {
+    private void maybeShowDataSaverInProductHelp(final FeatureEngagementTracker tracker) {
+        if (!tracker.shouldTriggerHelpUI(FeatureConstants.DATA_SAVER_DETAIL_FEATURE)) return;
+
         ViewAnchoredTextBubble textBubble = new ViewAnchoredTextBubble(getActivity(),
                 getActivity().getToolbarManager().getMenuButton(),
                 R.string.iph_data_saver_detail_text,
                 R.string.iph_data_saver_detail_accessibility_text);
         textBubble.setDismissOnTouchInteraction(true);
-        getActivity().getAppMenuHandler().setMenuHighlight(R.id.data_reduction_footer);
+        getActivity().getAppMenuHandler().setMenuHighlight(R.id.app_menu_footer);
         textBubble.addOnDismissListener(new OnDismissListener() {
             @Override
             public void onDismiss() {