[Payments] Use <meta-data> tag instead of intent filter data to detect supported payment methods.

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

Index: chrome/android/java/src/org/chromium/chrome/browser/payments/AndroidPaymentAppFinder.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/payments/AndroidPaymentAppFinder.java b/chrome/android/java/src/org/chromium/chrome/browser/payments/AndroidPaymentAppFinder.java
index 252fc4be2ab2e62592cecf48678b63e43db05033..cee3a513d7b251c84cbecf4c515005fec0cedb12 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/payments/AndroidPaymentAppFinder.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/payments/AndroidPaymentAppFinder.java
@@ -6,7 +6,6 @@ package org.chromium.chrome.browser.payments;
 
 import android.content.Intent;
 import android.content.pm.ResolveInfo;
-import android.net.Uri;
 import android.text.TextUtils;
 
 import org.chromium.base.Log;
@@ -41,16 +40,24 @@ public class AndroidPaymentAppFinder implements ManifestVerifyCallback {
     /* package */ static final String ACTION_IS_READY_TO_PAY =
                           "org.chromium.intent.action.IS_READY_TO_PAY";
 
-    /** The name of the intent for the action of paying using "basic-card" method. */
-    /* package */ static final String ACTION_PAY_BASIC_CARD =
-                          "org.chromium.intent.action.PAY_BASIC_CARD";
-
     /**
      * The basic-card payment method name used by merchant and defined by W3C:
      * https://w3c.github.io/webpayments-methods-card/#method-id
      */
     /* package */ static final String BASIC_CARD_PAYMENT_METHOD = "basic-card";
 
+    /**
+     * Meta data name of an app's supported payment method names.
+     */
+    static final String META_DATA_NAME_OF_PAYMENT_METHOD_NAMES =
+            "org.chromium.payment_method_names";
+
+    /**
+     * Meta data name of an app's supported default payment method name.
+     */
+    static final String META_DATA_NAME_OF_DEFAULT_PAYMENT_METHOD_NAME =
+            "org.chromum.default_payment_method_name";
+
     /** The maximum number of payment method manifests to download. */
     private static final int MAX_NUMBER_OF_MANIFESTS = 10;
 
@@ -151,22 +158,42 @@ public class AndroidPaymentAppFinder implements ManifestVerifyCallback {
     }
 
     private void findAndroidPaymentApps() {
+        Intent payIntent = new Intent(AndroidPaymentApp.ACTION_PAY);
+        List<ResolveInfo> apps =
+                mPackageManagerDelegate.getActivitiesThatCanRespondToIntent(payIntent);
+        if (apps.isEmpty()) {
+            onSearchFinished();
+            return;
+        }
+
+        List<String[]> appSupportedMethods = new ArrayList<String[]>();
+        for (int i = 0; i < apps.size(); i++) {
+            appSupportedMethods.add(mPackageManagerDelegate.getStringArrayMetaData(
+                    apps.get(i).activityInfo.packageName, META_DATA_NAME_OF_PAYMENT_METHOD_NAMES));
+        }
+
+        List<String> appSupportedDefaultMethods = new ArrayList<String>();
+        for (int i = 0; i < apps.size(); i++) {
+            appSupportedDefaultMethods.add(
+                    mPackageManagerDelegate.getStringMetaData(apps.get(i).activityInfo.packageName,
+                            META_DATA_NAME_OF_DEFAULT_PAYMENT_METHOD_NAME));
+        }
+
         List<PaymentManifestVerifier> verifiers = new ArrayList<>();
         if (!mPaymentMethods.isEmpty()) {

[please use gerrit instead, 2017/03/31 15:47:08]

This check seems redundant now. Let's remove it.

[gogerald1, 2017/03/31 16:18:43]

Why? mPaymentMethods is merchant queried methods which haven't been checked
before.

[please use gerrit instead, 2017/03/31 16:26:30]

It's redundant because the for loop on the next line is a no-op for empty
mPaymentMethods.

[gogerald1, 2017/03/31 16:28:54]

yes, my bad, updated in the new patch

-            Intent payIntent = new Intent(AndroidPaymentApp.ACTION_PAY);
             for (URI methodName : mPaymentMethods) {
-                payIntent.setData(Uri.parse(methodName.toString()));
-                List<ResolveInfo> apps =
-                        mPackageManagerDelegate.getActivitiesThatCanRespondToIntent(payIntent);
-                if (apps.isEmpty()) continue;
+                List<ResolveInfo> supportedApps = findOutAppsSupportTheGivenPaymentMethod(apps,
+                        appSupportedMethods, appSupportedDefaultMethods, methodName.toString());
+                if (supportedApps.isEmpty()) continue;
 
                 // Start the parser utility process as soon as possible, once we know that a
                 // manifest file needs to be parsed. The startup can take up to 2 seconds.
                 if (!mParser.isUtilityProcessRunning()) mParser.startUtilityProcess();
 
-                verifiers.add(new PaymentManifestVerifier(methodName, apps, mDownloader, mParser,
-                        mPackageManagerDelegate, this /* callback */));
-                mPendingApps.put(methodName, new HashSet<>(apps));
+                verifiers.add(new PaymentManifestVerifier(methodName, supportedApps, mDownloader,
+                        mParser, mPackageManagerDelegate, this /* callback */));
+                mPendingApps.put(methodName, new HashSet<>(supportedApps));
+
                 if (verifiers.size() == MAX_NUMBER_OF_MANIFESTS) {
                     Log.d(TAG, "Reached maximum number of allowed payment app manifests.");
                     break;
@@ -175,12 +202,11 @@ public class AndroidPaymentAppFinder implements ManifestVerifyCallback {
         }
 
         if (mQueryBasicCard) {
-            Intent basicCardPayIntent = new Intent(ACTION_PAY_BASIC_CARD);
-            List<ResolveInfo> apps =
-                    mPackageManagerDelegate.getActivitiesThatCanRespondToIntent(basicCardPayIntent);
-            for (int i = 0; i < apps.size(); i++) {
+            List<ResolveInfo> supportedApps = findOutAppsSupportTheGivenPaymentMethod(apps,
+                    appSupportedMethods, appSupportedDefaultMethods, BASIC_CARD_PAYMENT_METHOD);
+            for (int i = 0; i < supportedApps.size(); i++) {
                 // Chrome does not verify app manifests for "basic-card" support.
-                onValidPaymentApp(BASIC_CARD_PAYMENT_METHOD, apps.get(i));
+                onValidPaymentApp(BASIC_CARD_PAYMENT_METHOD, supportedApps.get(i));
             }
         }
 
@@ -194,6 +220,32 @@ public class AndroidPaymentAppFinder implements ManifestVerifyCallback {
         }
     }
 
+    private List<ResolveInfo> findOutAppsSupportTheGivenPaymentMethod(List<ResolveInfo> apps,

[please use gerrit instead, 2017/03/31 15:47:08]

static?

[please use gerrit instead, 2017/03/31 15:47:08]

filterAppsByMethodName().

[gogerald1, 2017/03/31 16:18:43]

Done.

[gogerald1, 2017/03/31 16:18:43]

Done.

+            List<String[]> appsMethods, List<String> appsDefaultMethods, String targetMethodName) {

[please use gerrit instead, 2017/03/31 15:47:08]

Let's pass URI data type in as many places as possible: "URI targetMethodName".

[gogerald1, 2017/03/31 16:18:43]

Looks not good since this interface is also used for basic-card

+        assert apps.size() == appsMethods.size();
+        assert apps.size() == appsDefaultMethods.size();
+
+        // Note that apps, appsMethods and appsDefaultMethods must have the same size. And the
+        // information at the same index must correspond to the same app.
+        List<ResolveInfo> supportedApps = new ArrayList<ResolveInfo>();
+        for (int i = 0; i < apps.size(); i++) {
+            if (targetMethodName.equalsIgnoreCase(appsDefaultMethods.get(i))) {

[please use gerrit instead, 2017/03/31 15:47:08]

Don't ignore case. Let's be strict.

[gogerald1, 2017/03/31 16:18:43]

Done. I am worried that the merchant might use upper case (like the first
character 'H'), is it allowed in the spec? or do we lower cased them somewhere?

[please use gerrit instead, 2017/03/31 16:26:30]

We prohibit variations in the spec as much as possible. Variations breed
security holes and noncompatible implementaitons. See
http://queue.acm.org/detail.cfm?id=1999945

+                supportedApps.add(apps.get(i));
+                continue;
+            }
+
+            String[] methods = appsMethods.get(i);
+            if (methods == null) continue;
+            for (int j = 0; j < methods.length; j++) {
+                if (targetMethodName.equalsIgnoreCase(methods[j])) {
+                    supportedApps.add(apps.get(i));
+                    break;
+                }
+            }
+        }
+        return supportedApps;
+    }
+
     @Override
     public void onValidPaymentApp(URI methodName, ResolveInfo resolveInfo) {
         onValidPaymentApp(methodName.toString(), resolveInfo);