[Custom Tabs]Add API for updating action button as ContentProvider

chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabUpdater.java

Index: chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabUpdater.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabUpdater.java b/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabUpdater.java
new file mode 100644
index 0000000000000000000000000000000000000000..61d6f8ee43df00e406065f0861d7caf396679700
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabUpdater.java
@@ -0,0 +1,94 @@
+// Copyright 2015 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.chrome.browser.customtabs;
+
+import android.content.ContentProvider;
+import android.content.ContentValues;
+import android.database.Cursor;
+import android.graphics.Bitmap;
+import android.net.Uri;
+import android.os.Bundle;
+import android.os.IBinder;
+import android.support.customtabs.CustomTabsIntent;
+import android.text.TextUtils;
+
+import org.chromium.base.ThreadUtils;
+import org.chromium.chrome.browser.util.IntentUtils;
+
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutionException;
+
+/**
+ * A {@link ContentProvider} that interacts with clients to for updating existing custom tabs.
+ */
+public class CustomTabUpdater extends ContentProvider {
+    @Override
+    public boolean onCreate() {
+        return true;
+    }
+
+    @Override
+    public Bundle call(String method, String arg, Bundle extras) {
+        if (TextUtils.equals(method, CustomTabsIntent.METHOD_UPDATE_ACTION_BUTTON)) {
+            Bundle actionButtonBundle = extras
+                    .getBundle(CustomTabsIntent.EXTRA_ACTION_BUTTON_BUNDLE);
+            if (actionButtonBundle == null) return constructResult(false);
+
+            final Bitmap bitmap = ActionButtonParams.tryParseBitmapFromBundle(getContext(),
+                    actionButtonBundle);
+            final String description = ActionButtonParams
+                    .tryParseDescriptionFromBundle(actionButtonBundle);
+            if (bitmap == null || description == null) return constructResult(false);
+
+            final IBinder session = IntentUtils.safeGetBinder(extras,
+                    CustomTabsIntent.EXTRA_SESSION);

[Ian Wen, 2015/08/31 22:35:33]

Here an alternative approach is to call Binder.getCallingUid(), and in
CustomTabContentHandler, we store the uid along side with the IBinder to match
it.

Yet what worries me is that one of Grace's original thoughts was not implemented
in this CL: the client still must have a service connection anyway, because
either the uid or the IBinder are recorded by the time the service creates the
activity. If the custom tab was initiated by a pure View intent, then there is
no way we could grab any information about the client app.

[Benoit L, 2015/09/01 16:45:10]

Novice question: are we sure that Binder.getCallingUid() returns something
meaningful here? AFAIK, it only returns something else than your own UID inside
a Binder transaction. Is is the case here?

+
+            try {
+                return constructResult(ThreadUtils.runOnUiThreadBlocking(new Callable<Boolean>() {
+                    @Override
+                    public Boolean call() throws Exception {
+                        return CustomTabActivity.updateActionButton(session, bitmap, description);
+                    }
+                }));
+            } catch (ExecutionException e) {
+                return constructResult(false);
+            }
+        }
+        return constructResult(false);
+    }
+
+    private Bundle constructResult(boolean success) {
+        Bundle result = new Bundle();
+        result.putBoolean(CustomTabsIntent.EXTRA_RETURN, success);
+        return result;
+    }
+
+    @Override
+    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
+            String sortOrder) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public String getType(Uri uri) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public Uri insert(Uri uri, ContentValues values) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public int delete(Uri uri, String selection, String[] selectionArgs) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
+        throw new UnsupportedOperationException();
+    }
+
+}