[gIRA] Add the ability to find WebAPKs by manifestURLs.

This is limited to bound WebAPKs. This is the first step to make WebAPKs
discoverable via getInstalledRelatedApps.

Bug: 1043970
Change-Id: I1cbb86159d15554c129894b6c405c1efefa42587
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2012287
Commit-Queue: Rayan Kanso <rayankans@chromium.org>
Reviewed-by: Peter Kotwicz <pkotwicz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#734214}

chrome/android/webapk/libs/client/src/org/chromium/webapk/lib/client/WebApkValidator.java

@@ -7,6 +7,7 @@ package org.chromium.webapk.lib.client;
 import static org.chromium.webapk.lib.common.WebApkConstants.WEBAPK_PACKAGE_PREFIX;
 import static org.chromium.webapk.lib.common.WebApkMetaDataKeys.SCOPE;
 import static org.chromium.webapk.lib.common.WebApkMetaDataKeys.START_URL;
+import static org.chromium.webapk.lib.common.WebApkMetaDataKeys.WEB_MANIFEST_URL;
 
 import android.content.Context;
 import android.content.Intent;
@@ -356,6 +357,40 @@ public class WebApkValidator {
         }
     }
 
+    /**
+     * Determines if a bound WebAPK generated from |manifestUrl| is installed on the device.
+     * @param context The context to use to check whether WebAPK is valid.
+     * @param manifestUrl The URL of the manifest that was used to generate the WebAPK.
+     * @return The WebAPK's package name if installed, or null otherwise.
+     */
+    public static @Nullable String queryBoundWebApkForManifestUrl(
+            Context context, String manifestUrl) {
+        assert manifestUrl != null;
+
+        List<PackageInfo> packages = context.getPackageManager().getInstalledPackages(
+                PackageManager.GET_SIGNATURES | PackageManager.GET_META_DATA);
+
+        // Filter out unbound & invalid WebAPKs.
+        for (int i = 0; i < packages.size(); i++) {
+            PackageInfo info = packages.get(i);
+
+            if (!verifyV1WebApk(info, info.packageName)) {
+                continue;
+            }
+
+            // |info| belongs to a valid, bound, WebAPK. Check that the metadata contains
+            // |manifestUrl|.
+            String packageManifestUrl = info.applicationInfo.metaData.getString(WEB_MANIFEST_URL);
+            if (!TextUtils.equals(packageManifestUrl, manifestUrl)) {
+                continue;
+            }
+
+            return info.packageName;
+        }
+
+        return null;
+    }
+
     /**
      * Initializes the WebApkValidator.
      * @param expectedSignature V1 WebAPK RSA signature.