Supervised user web restrictions content provider

chrome/android/java/src/org/chromium/chrome/browser/superviseduser/SupervisedUserContentProvider.java

Index: chrome/android/java/src/org/chromium/chrome/browser/superviseduser/SupervisedUserContentProvider.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/superviseduser/SupervisedUserContentProvider.java b/chrome/android/java/src/org/chromium/chrome/browser/superviseduser/SupervisedUserContentProvider.java
new file mode 100644
index 0000000000000000000000000000000000000000..ae5e479212a97f154131e06881fc71f4bb6983fb
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/superviseduser/SupervisedUserContentProvider.java
@@ -0,0 +1,133 @@
+// 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.superviseduser;
+
+import android.os.Bundle;
+import android.util.Pair;
+
+import org.chromium.base.ThreadUtils;
+import org.chromium.base.VisibleForTesting;
+import org.chromium.base.annotations.CalledByNative;
+import org.chromium.base.library_loader.LibraryProcessType;
+import org.chromium.base.library_loader.ProcessInitException;
+import org.chromium.components.webrestriction.WebRestrictionsContentProvider;
+import org.chromium.content.browser.BrowserStartupController;
+
+import java.util.concurrent.SynchronousQueue;
+
+/**
+ * Content provider for telling other apps (e.g. WebView apps) about the supervised user URL filter.
+ */
+public class SupervisedUserContentProvider extends WebRestrictionsContentProvider {
+    private long mNativeSupervisedUserContentProvider = 0;
+
+    private SynchronousQueue<Pair<Boolean, String>> mResultQueue;

[Bernhard Bauer, 2015/12/14 17:58:37]

Can you make this final?

[aberent, 2015/12/16 15:20:37]

Done.

+
+    public SupervisedUserContentProvider() {
+        super();

[Bernhard Bauer, 2015/12/14 17:58:37]

This can be removed, right?

[aberent, 2015/12/16 15:20:37]

Done.

+        mResultQueue = new SynchronousQueue<Pair<Boolean, String>>();

[Bernhard Bauer, 2015/12/14 17:58:37]

Initialize this where it's declared?

[aberent, 2015/12/16 15:20:37]

Done.

+    }
+
+    private long getSupervisedUserContentProvider() throws ProcessInitException {
+        if (mNativeSupervisedUserContentProvider != 0) {
+            return mNativeSupervisedUserContentProvider;
+        }
+
+        BrowserStartupController.get(getContext(), LibraryProcessType.PROCESS_BROWSER)
+                .startBrowserProcessesSync(false);
+
+        mNativeSupervisedUserContentProvider = nativeCreateSupervisedUserContentProvider();
+        return mNativeSupervisedUserContentProvider;
+    }
+
+    @VisibleForTesting
+    void setNativeSupervisedUserContentProviderForTesting(long nativeProvider) {
+        mNativeSupervisedUserContentProvider = nativeProvider;
+    }
+
+    @Override
+    protected synchronized Pair<Boolean, String> shouldProceed(final String url) {

[Bernhard Bauer, 2015/12/14 17:58:37]

Synchronize on a member variable of type Object. Doing this will cause a
FindBugs error.

[aberent, 2015/12/16 15:20:37]

Done.

+        ThreadUtils.runOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    nativeShouldProceed(getSupervisedUserContentProvider(), url);
+                } catch (ProcessInitException e) {
+                    onQueryComplete(false, null);
+                }
+            }
+        });
+        try {
+            return mResultQueue.take();

[Bernhard Bauer, 2015/12/14 17:58:37]

Can you add a comment that this will block until another thread puts something
in, just so that a casual reader can understand the flow of control?

[aberent, 2015/12/16 15:20:37]

Done.

+        } catch (InterruptedException e) {
+            return new Pair<Boolean, String>(false, null);
+        }
+    }
+
+    @Override
+    protected boolean canInsert() {
+        // Chromium always allows insertion requests.
+        return true;
+    }
+
+    @Override
+    protected void requestInsert(final String url) {
+        ThreadUtils.runOnUiThreadBlocking(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    nativeRequestInsert(getSupervisedUserContentProvider(), url);
+                } catch (ProcessInitException e) {
+                    // There is no way of returning anything sensible here, so ignore the error and
+                    // do nothing.
+                }
+            }
+        });
+    }
+
+    @VisibleForTesting
+    @Override
+    public Bundle call(String method, String arg, Bundle bundle) {
+        if (method == "setFilterForTesting") setFilterForTesting();
+        return null;
+    }
+
+    @VisibleForTesting
+    void setFilterForTesting() {
+        ThreadUtils.runOnUiThreadBlocking(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    nativeSetFilterForTesting(getSupervisedUserContentProvider());
+                } catch (ProcessInitException e) {
+                    // There is no way of returning anything sensible here, so ignore the error and
+                    // do nothing.
+                }
+            }
+        });
+    }
+
+    @VisibleForTesting
+    @CalledByNative
+    void onQueryComplete(boolean result, String errorMessage) {
+        mResultQueue.add(new Pair<Boolean, String>(result, errorMessage));
+    }
+
+    @VisibleForTesting
+    @CalledByNative
+    void onSupervisedUserFilterUpdated() {
+        onFilterChanged();
+    }
+
+    @VisibleForTesting native long nativeCreateSupervisedUserContentProvider();
+
+    @VisibleForTesting
+    native void nativeShouldProceed(long nativeSupervisedUserContentProvider, String url);
+
+    @VisibleForTesting
+    native void nativeRequestInsert(long nativeSupervisedUserContentProvider, String url);
+
+    private native void nativeSetFilterForTesting(long nativeSupervisedUserContentProvider);
+}