[PaymentHandler] Tapping on scrim not to dismiss sheet

Context: The Bottom-sheet based PaymentHandler UI is based on the
bottom-sheet, as its name suggested. For a ChromeActivity's
bottom-sheet, when users tap on the scrim, the default behavior is
dismissing the sheet. This behavior, however, would increase the avg
time for users to finish a transaction, because users may accidentally
tap to close the sheet and has to redo the transaction.

Old behavior: tapping the scrim of Payment Handler UI dismisses the
sheet.

Change: Since the sheet dismissal behavior is defined in the
onScrimClick method of the BottomSheet's default scrim-observer,
we override this method to bypass the dismissal.

New behavior: tapping the scrim of Payment Handler UI wouldn't dismiss
the sheet.

Bug: 1029815

Change-Id: If15ab2c7f293387fbc546c79006b2d2e811d6b38
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1935431Reviewed-by: Matthew Jones <mdjones@chromium.org>
Commit-Queue: Liquan (Max) Gu <maxlg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#723447}

chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentRequestImpl.java

@@ -52,6 +52,9 @@ import org.chromium.chrome.browser.tabmodel.TabModelObserver;
 import org.chromium.chrome.browser.tabmodel.TabModelSelector;
 import org.chromium.chrome.browser.tabmodel.TabModelSelectorObserver;
 import org.chromium.chrome.browser.util.UrlConstants;
+import org.chromium.chrome.browser.widget.ScrimView;
+import org.chromium.chrome.browser.widget.ScrimView.EmptyScrimObserver;
+import org.chromium.chrome.browser.widget.ScrimView.ScrimParams;
 import org.chromium.chrome.browser.widget.prefeditor.Completable;
 import org.chromium.chrome.browser.widget.prefeditor.EditableOption;
 import org.chromium.components.payments.CurrencyFormatter;
@@ -1421,11 +1424,20 @@ public class PaymentRequestImpl
     public void onPaymentHandlerUiClosed() {
         mPaymentUisShowStateReconciler.onPaymentHandlerUiClosed();
         mPaymentHandlerUi = null;
+        ChromeActivity.fromWebContents(mWebContents).getScrim().hideScrim(true);
     }
 
     @Override
     public void onPaymentHandlerUiShown() {
+        assert mPaymentHandlerUi != null;
         mPaymentUisShowStateReconciler.onPaymentHandlerUiShown();
+        // Using an empty scrim observer is to avoid the dismissal of the bottom-sheet on tapping.
+        ScrimParams params = ChromeActivity.fromWebContents(mWebContents)
+                                     .getBottomSheetController()
+                                     .createScrimParams(new EmptyScrimObserver());
+        ScrimView scrim = ChromeActivity.fromWebContents(mWebContents).getScrim();
+        scrim.showScrim(params);
+        scrim.setViewAlpha(0);
     }
 
     @Override

chrome/android/java/src/org/chromium/chrome/browser/payments/handler/PaymentHandlerView.java

@@ -102,6 +102,11 @@ import org.chromium.ui.base.ActivityWindowAndroid;
         return mToolbarView;
     }
 
+    @Override
+    public boolean hasCustomScrimLifecycle() {
+        return true;
+    }
+
     @Override
     public int getVerticalScrollOffset() {
         return 0;

chrome/android/java/src/org/chromium/chrome/browser/widget/ScrimView.java

@@ -137,6 +137,17 @@ public class ScrimView extends View implements View.OnClickListener {
         void onScrimVisibilityChanged(boolean visible);
     }
 
+    /**
+     * An empty implementation of the ScrimObserver interface.
+     */
+    public static class EmptyScrimObserver implements ScrimObserver {
+        @Override
+        public void onScrimClick() {}
+
+        @Override
+        public void onScrimVisibilityChanged(boolean visible) {}
+    }
+
     /** The duration for the fading animation. */
     private static final int FADE_DURATION_MS = 300;
 

chrome/android/java/src/org/chromium/chrome/browser/widget/bottomsheet/BottomSheetController.java

@@ -365,6 +365,15 @@ public class BottomSheetController implements Destroyable {
         mSheetInitializer = null;
     }
 
+    /**
+     * Create a ScrimParams anchoring on the bottom-sheet view.
+     * @param scrimObserver The scrimObserver to set for the ScrimParams.
+     */
+    public ScrimParams createScrimParams(ScrimObserver scrimObserver) {
+        return new ScrimParams(/*anchorView=*/mBottomSheet, /*showInFrontOfAnchorView=*/false,
+                /*affectsStatusBar=*/true, /*topMargin=*/0, /*observer*/ scrimObserver);
+    }
+
     // Destroyable implementation.
     @Override
     public void destroy() {