[WebLayer] PRService no longer asserts use-after-close

Now that PRService has implemented several interfaces, it's hard to
demand the callers that they should no longer use the class after
PRService has been closed because the callers are only responsible for
the interfaces. What if the interface provides hasClosed() and requires
the callers to check before use? It could complicate the caller code
and the interfaces (for adding hasClosed to about 10 interfaces that
PRService would implement).

For this reason, this CL is to make PRService more flexible to use.
Instead of asserting that mBrowserPaymentRequest and mClient should not
be used after PRService is closed, PRService will just early return.

Bug: 1146565

Change-Id: Ifd5e8a73ea66bdc0b3c615695f2fc3009d4f62ae
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2522980
Commit-Queue: Liquan (Max) Gu <maxlg@chromium.org>
Reviewed-by: Rouslan Solomakhin <rouslan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825199}

components/payments/content/android/java/src/org/chromium/components/payments/PaymentRequestService.java

@@ -806,15 +806,9 @@ public class PaymentRequestService
                 || sIsLocalHasEnrolledInstrumentQueryQuotaEnforcedForTest;
     }
 
-    /** @return Whether the instrument has been enrolled. */
-    public boolean getHasEnrolledInstrument() {
-        return mHasEnrolledInstrument;
-    }
-
     // Implements PaymentAppFactoryDelegate:
     @Override
     public void onCanMakePaymentCalculated(boolean canMakePayment) {
-        if (mBrowserPaymentRequest == null) return;
         mCanMakePayment = canMakePayment;
         if (!mIsCanMakePaymentResponsePending) return;
         // canMakePayment doesn't need to wait for all apps to be queried because it only needs to
@@ -860,9 +854,7 @@ public class PaymentRequestService
      * PaymentRequest#show} for the parameters' specification.
      */
     /* package */ void show(boolean isUserGesture, boolean waitForUpdatedDetails) {
-        // Every caller should stop referencing this class once close() is called.
-        assert mBrowserPaymentRequest != null;
-
+        if (mBrowserPaymentRequest == null) return;
         mBrowserPaymentRequest.show(isUserGesture, waitForUpdatedDetails);
     }
 
@@ -871,9 +863,7 @@ public class PaymentRequestService
      * @param details The details that the merchant provides to update the payment request.
      */
     /* package */ void updateWith(PaymentDetails details) {
-        // Every caller should stop referencing this class once close() is called.
-        assert mBrowserPaymentRequest != null;
-
+        if (mBrowserPaymentRequest == null) return;
         mBrowserPaymentRequest.updateWith(details);
     }
 
@@ -881,9 +871,7 @@ public class PaymentRequestService
      * The component part of the {@link PaymentRequest#onPaymentDetailsNotUpdated} implementation.
      */
     /* package */ void onPaymentDetailsNotUpdated() {
-        // Every caller should stop referencing this class once close() is called.
-        assert mBrowserPaymentRequest != null;
-
+        if (mBrowserPaymentRequest == null) return;
         mBrowserPaymentRequest.onPaymentDetailsNotUpdated();
     }
 
@@ -898,9 +886,7 @@ public class PaymentRequestService
 
     /** The component part of the {@link PaymentRequest#complete} implementation. */
     /* package */ void complete(int result) {
-        // Every caller should stop referencing this class once close() is called.
-        assert mBrowserPaymentRequest != null;
-
+        if (mBrowserPaymentRequest == null) return;
         mBrowserPaymentRequest.complete(result);
     }
 
@@ -909,9 +895,7 @@ public class PaymentRequestService
      * PaymentRequest#retry} for the parameters' specification.
      */
     /* package */ void retry(PaymentValidationErrors errors) {
-        // Every caller should stop referencing this class once close() is called.
-        assert mBrowserPaymentRequest != null;
-
+        if (mBrowserPaymentRequest == null) return;
         mBrowserPaymentRequest.retry(errors);
     }
 
@@ -949,9 +933,6 @@ public class PaymentRequestService
      * stop referencing this class after calling this method.
      */
     /* package */ void closeByRenderer() {
-        // Every caller should stop referencing this class once close() is called.
-        assert mBrowserPaymentRequest != null;
-
         mJourneyLogger.setAborted(AbortReason.MOJO_RENDERER_CLOSING);
         close();
         if (sObserverForTest != null) {
@@ -968,9 +949,6 @@ public class PaymentRequestService
      * @param e The mojo exception.
      */
     /* package */ void onConnectionError(MojoException e) {
-        // Every caller should stop referencing this class once close() is called.
-        assert mBrowserPaymentRequest != null;
-
         mJourneyLogger.setAborted(AbortReason.MOJO_CONNECTION_ERROR);
         close();
         if (sNativeObserverForTest != null) {
@@ -983,9 +961,6 @@ public class PaymentRequestService
      * @param debugMessage The debug message to be sent to the renderer.
      */
     /* package */ void abortForInvalidDataFromRenderer(String debugMessage) {
-        // Every caller should stop referencing this class once close() is called.
-        assert mBrowserPaymentRequest != null;
-
         mJourneyLogger.setAborted(AbortReason.INVALID_DATA_FROM_RENDERER);
         disconnectFromClientWithDebugMessage(debugMessage, PaymentErrorReason.USER_CANCEL);
     }
@@ -1001,14 +976,17 @@ public class PaymentRequestService
 
         mIsCurrentPaymentRequestShowing = false;
 
-        if (mBrowserPaymentRequest == null) return;
-        mBrowserPaymentRequest.close();
-        mBrowserPaymentRequest = null;
+        if (mBrowserPaymentRequest != null) {
+            mBrowserPaymentRequest.close();
+            mBrowserPaymentRequest = null;
+        }
 
         // mClient can be null only when this method is called from
         // PaymentRequestService#create().
-        if (mClient != null) mClient.close();
-        mClient = null;
+        if (mClient != null) {
+            mClient.close();
+            mClient = null;
+        }
 
         mOnClosedListener.run();
     }
@@ -1028,51 +1006,35 @@ public class PaymentRequestService
 
     /** Invokes {@link PaymentRequestClient.onShippingAddressChange}. */
     public void onShippingAddressChange(PaymentAddress address) {
-        // Every caller should stop referencing this class once close() is called.
-        assert mClient != null;
-
-        redactShippingAddress(address);
-        mClient.onShippingAddressChange(address);
+        if (mClient != null) {
+            redactShippingAddress(address);
+            mClient.onShippingAddressChange(address);
+        }
     }
 
     /** Invokes {@link PaymentRequestClient.onShippingOptionChange}. */
     public void onShippingOptionChange(String shippingOptionId) {
-        // Every caller should stop referencing this class once close() is called.
-        assert mClient != null;
-
-        mClient.onShippingOptionChange(shippingOptionId);
+        if (mClient != null) mClient.onShippingOptionChange(shippingOptionId);
     }
 
     /** Invokes {@link PaymentRequestClient.onPayerDetailChange}. */
     public void onPayerDetailChange(PayerDetail detail) {
-        // Every caller should stop referencing this class once close() is called.
-        assert mClient != null;
-
-        mClient.onPayerDetailChange(detail);
+        if (mClient != null) mClient.onPayerDetailChange(detail);
     }
 
     /** Invokes {@link PaymentRequestClient.onError}. */
     public void onError(int error, String errorMessage) {
-        // Every caller should stop referencing this class once close() is called.
-        assert mClient != null;
-
-        mClient.onError(error, errorMessage);
+        if (mClient != null) mClient.onError(error, errorMessage);
     }
 
     /** Invokes {@link PaymentRequestClient.onComplete}. */
     public void onComplete() {
-        // Every caller should stop referencing this class once close() is called.
-        assert mClient != null;
-
-        mClient.onComplete();
+        if (mClient != null) mClient.onComplete();
     }
 
     /** Invokes {@link PaymentRequestClient.warnNoFavicon}. */
     public void warnNoFavicon() {
-        // Every caller should stop referencing this class once close() is called.
-        assert mClient != null;
-
-        mClient.warnNoFavicon();
+        if (mClient != null) mClient.warnNoFavicon();
     }
 
     /**