android: Use Context.getDisplay on R

Context.getDisplay is new on R and will throw an exception when the
Context is not associated with a display. Use this exception to detect
this case instead of trying to unwrap the context to find an Activity.

Bug: 1116000
Change-Id: Ib900205b8ce8aceb21a9f705431e040aef0e6ddb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2354291
Commit-Queue: Bo <boliu@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#797878}

base/BUILD.gn

@@ -3577,6 +3577,7 @@ if (is_android) {
       "android/java/src/org/chromium/base/compat/ApiHelperForOMR1.java",
       "android/java/src/org/chromium/base/compat/ApiHelperForP.java",
       "android/java/src/org/chromium/base/compat/ApiHelperForQ.java",
+      "android/java/src/org/chromium/base/compat/ApiHelperForR.java",
       "android/java/src/org/chromium/base/library_loader/LegacyLinker.java",
       "android/java/src/org/chromium/base/library_loader/LibraryLoader.java",
       "android/java/src/org/chromium/base/library_loader/LibraryPrefetcher.java",

base/android/java/src/org/chromium/base/compat/ApiHelperForR.java

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.base.compat;
+
+import android.annotation.TargetApi;
+import android.content.Context;
+import android.os.Build;
+import android.view.Display;
+
+import org.chromium.base.annotations.VerifiesOnR;
+
+/**
+ * Utility class to use new APIs that were added in Q (API level 29). These need to exist in a
+ * separate class so that Android framework can successfully verify classes without
+ * encountering the new APIs.
+ */
+@VerifiesOnR
+@TargetApi(Build.VERSION_CODES.R)
+public final class ApiHelperForR {
+    private ApiHelperForR() {}
+
+    public static Display getDisplay(Context context) throws UnsupportedOperationException {
+        return context.getDisplay();
+    }
+}

ui/android/java/src/org/chromium/ui/display/DisplayAndroidManager.java

@@ -8,17 +8,18 @@ import android.annotation.SuppressLint;
 import android.content.Context;
 import android.hardware.display.DisplayManager;
 import android.hardware.display.DisplayManager.DisplayListener;
+import android.os.Build;
 import android.util.SparseArray;
 import android.view.Display;
 import android.view.WindowManager;
 
-import org.chromium.base.BuildInfo;
 import org.chromium.base.ContextUtils;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
 import org.chromium.base.annotations.MainDex;
 import org.chromium.base.annotations.NativeMethods;
+import org.chromium.base.compat.ApiHelperForR;
 
 /**
  * DisplayAndroidManager is a class that informs its observers Display changes.
@@ -97,9 +98,14 @@ public class DisplayAndroidManager {
     }
 
     public static Display getDefaultDisplayForContext(Context context) {
-        // TODO(boliu): There are other valid display context though they require R APIs to query.
-        // This is good enough for now since nothing in chromium calls Context.createDisplayContext.
-        if (BuildInfo.targetsAtLeastR() && ContextUtils.activityFromContext(context) == null) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+            Display display = null;
+            try {
+                display = ApiHelperForR.getDisplay(context);
+            } catch (UnsupportedOperationException e) {
+                // Context is not associated with a display.
+            }
+            if (display != null) return display;
             return getGlobalDefaultDisplay();
         }
         return getDisplayForContextNoChecks(context);