Resubmit 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..a07b5bcc280eb735f0f15fd6f97b33f51e6c0773
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/superviseduser/SupervisedUserContentProvider.java
@@ -0,0 +1,178 @@
+// 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.CountDownLatch;
+
+/**
+ * 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 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;
+    }
+
+    @VisibleForTesting
+    static class SupervisedUserQueryReply {
+        final CountDownLatch mLatch = new CountDownLatch(1);
+        private Pair<Boolean, String> mResult;
+        @VisibleForTesting
+        @CalledByNative("SupervisedUserQueryReply")
+        void onQueryComplete(boolean result, String errorMessage) {
+            // This must be called precisely once per query.
+            assert mResult == null;
+            mResult = new Pair<Boolean, String>(result, errorMessage);
+            mLatch.countDown();
+        }
+        Pair<Boolean, String> getResult() throws InterruptedException {
+            mLatch.await();
+            return mResult;
+        }
+    }
+
+    @Override
+    protected Pair<Boolean, String> shouldProceed(final String url) {
+        // This will be called on multiple threads (but never the UI thread),
+        // see http://developer.android.com/guide/components/processes-and-threads.html#ThreadSafe.
+        // The reply comes back on a different thread (possibly the UI thread) some time later.
+        // As such it needs to correctly match the replies to the calls. It does this by creating a
+        // reply object for each query, and passing this through the callback structure. The reply
+        // object also handles waiting for the reply.
+        final SupervisedUserQueryReply queryReply = new SupervisedUserQueryReply();
+        ThreadUtils.runOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    nativeShouldProceed(getSupervisedUserContentProvider(), queryReply, url);
+                } catch (ProcessInitException e) {
+                    queryReply.onQueryComplete(false, null);
+                }
+            }
+        });
+        try {
+            // This will block until an onQueryComplete call on a different thread adds
+            // something to the queue.
+            return queryReply.getResult();
+        } catch (InterruptedException e) {
+            return new Pair<Boolean, String>(false, null);
+        }
+    }
+
+    @Override
+    protected boolean canInsert() {
+        // Chrome always allows insertion requests.
+        return true;
+    }
+
+    @VisibleForTesting
+    static class SupervisedUserInsertReply {
+        final CountDownLatch mLatch = new CountDownLatch(1);
+        boolean mResult;
+        @VisibleForTesting
+        @CalledByNative("SupervisedUserInsertReply")
+        void onInsertRequestSendComplete(boolean result) {
+            // This must be called precisely once per query.
+            assert mLatch.getCount() == 1;
+            mResult = result;
+            mLatch.countDown();
+        }
+        boolean getResult() throws InterruptedException {
+            mLatch.await();
+            return mResult;
+        }
+    }
+
+    @Override
+    protected boolean requestInsert(final String url) {
+        // This will be called on multiple threads (but never the UI thread),
+        // see http://developer.android.com/guide/components/processes-and-threads.html#ThreadSafe.
+        // The reply comes back on a different thread (possibly the UI thread) some time later.
+        // As such it needs to correctly match the replies to the calls. It does this by creating a
+        // reply object for each query, and passing this through the callback structure. The reply
+        // object also handles waiting for the reply.
+        final SupervisedUserInsertReply insertReply = new SupervisedUserInsertReply();
+        ThreadUtils.runOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    nativeRequestInsert(getSupervisedUserContentProvider(), insertReply, url);
+                } catch (ProcessInitException e) {
+                    insertReply.onInsertRequestSendComplete(false);
+                }
+            }
+        });
+        try {
+            return insertReply.getResult();
+        } catch (InterruptedException e) {
+            return false;
+        }
+    }
+
+    @VisibleForTesting
+    @Override
+    public Bundle call(String method, String arg, Bundle bundle) {
+        if (method.equals("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 onSupervisedUserFilterUpdated() {
+        onFilterChanged();
+    }
+
+    @VisibleForTesting native long nativeCreateSupervisedUserContentProvider();
+
+    @VisibleForTesting
+    native void nativeShouldProceed(long nativeSupervisedUserContentProvider,
+            SupervisedUserQueryReply queryReply, String url);
+
+    @VisibleForTesting
+    native void nativeRequestInsert(long nativeSupervisedUserContentProvider,
+            SupervisedUserInsertReply insertReply, String url);
+
+    private native void nativeSetFilterForTesting(long nativeSupervisedUserContentProvider);
+}