Upstream Chrome for Android Cast.

chrome/android/java/src/org/chromium/chrome/browser/media/remote/MediaUrlResolver.java

Index: chrome/android/java/src/org/chromium/chrome/browser/media/remote/MediaUrlResolver.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/media/remote/MediaUrlResolver.java b/chrome/android/java/src/org/chromium/chrome/browser/media/remote/MediaUrlResolver.java
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index 0000000000000000000000000000000000000000..133b5061844cfd25ea38e978bb6dc8e9fedc8867
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+++ b/chrome/android/java/src/org/chromium/chrome/browser/media/remote/MediaUrlResolver.java
@@ -0,0 +1,168 @@
+// Copyright 2013 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.media.remote;
+
+import android.content.Context;
+import android.net.Uri;
+import android.os.AsyncTask;
+import android.text.TextUtils;
+import android.util.Log;
+
+import org.apache.http.Header;
+import org.apache.http.message.BasicHeader;
+import org.chromium.chrome.browser.ChromiumApplication;
+
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.net.MalformedURLException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.util.Arrays;
+
+/**
+ * Resolves the final URL if it's a redirect. Works asynchronously, uses HTTP
+ * HEAD request to determine if the URL is redirected.
+ */
+public class MediaUrlResolver extends AsyncTask<Void, Void, MediaUrlResolver.Result> {
+
+    /**
+     * The interface to get the initial URI with cookies from and pass the final
+     * URI to.
+     */
+    public interface Delegate {
+        /**
+         * @return the original URL to resolve.
+         */
+        Uri getUri();
+
+        /**
+         * @return the cookies to fetch the URL with.
+         */
+        String getCookies();
+
+        /**
+         * Passes the resolved URL to the delegate.
+         *
+         * @param uri the resolved URL.
+         */
+        void setUri(Uri uri, Header[] headers);
+    }
+
+
+    protected static final class Result {
+        private final String mUri;
+        private final Header[] mRelevantHeaders;
+
+        public Result(String uri, Header[] relevantHeaders) {
+            mUri = uri;
+            mRelevantHeaders =
+                    relevantHeaders != null
+                    ? Arrays.copyOf(relevantHeaders, relevantHeaders.length)
+                    : null;
+        }
+
+        public String getUri() {
+            return mUri;
+        }
+
+        public Header[] getRelevantHeaders() {
+            return mRelevantHeaders != null
+                    ? Arrays.copyOf(mRelevantHeaders, mRelevantHeaders.length)
+                    : null;
+        }
+    }
+
+    private static final String TAG = "MediaUrlResolver";
+
+    private static final String CORS_HEADER_NAME = "Access-Control-Allow-Origin";
+    private static final String COOKIES_HEADER_NAME = "Cookies";
+    private static final String USER_AGENT_HEADER_NAME = "User-Agent";
+    private static final String RANGE_HEADER_NAME = "Range";
+
+    // We don't want to necessarily fetch the whole video but we don't want to miss the CORS header.
+    // Assume that 64k should be more than enough to keep all the headers.
+    private static final String RANGE_HEADER_VALUE = "bytes: 0-65536";
+
+    private final Context mContext;
+    private final Delegate mDelegate;
+
+    /**
+     * The constructor
+     * @param context the context to use to resolve the URL
+     * @param delegate The customer for this URL resolver.
+     */
+    public MediaUrlResolver(Context context, Delegate delegate) {
+        mContext = context;
+        mDelegate = delegate;
+    }
+
+    @Override
+    protected MediaUrlResolver.Result doInBackground(Void... params) {
+        Uri uri = mDelegate.getUri();
+        String url = uri.toString();
+        Header[] relevantHeaders = null;
+        String cookies = mDelegate.getCookies();
+        String userAgent = ChromiumApplication.getBrowserUserAgent();
+        // URL may already be partially percent encoded; double percent encoding will break
+        // things, so decode it before sanitizing it.
+        String sanitizedUrl = sanitizeUrl(Uri.decode(url));
+
+        // If we failed to sanitize the URL (e.g. because the host name contains underscores) then
+        // HttpURLConnection won't work,so we can't follow redirections. Just try to use it as is.
+        // TODO (aberent): Find out if there is a way of following redirections that is not so
+        // strict on the URL format.
+        if (!sanitizedUrl.equals("")) {
+            HttpURLConnection urlConnection = null;
+            try {
+                URL requestUrl = new URL(sanitizedUrl);
+                urlConnection = (HttpURLConnection) requestUrl.openConnection();
+                if (!TextUtils.isEmpty(cookies)) {
+                    urlConnection.setRequestProperty(COOKIES_HEADER_NAME, cookies);
+                }
+                urlConnection.setRequestProperty(USER_AGENT_HEADER_NAME, userAgent);
+                urlConnection.setRequestProperty(RANGE_HEADER_NAME, RANGE_HEADER_VALUE);
+
+                // This triggers resolving the URL and receiving the headers.
+                urlConnection.getHeaderFields();
+
+                url = urlConnection.getURL().toString();
+                String corsHeader = urlConnection.getHeaderField(CORS_HEADER_NAME);
+                if (corsHeader != null) {
+                    relevantHeaders = new Header[1];
+                    relevantHeaders[0] = new BasicHeader(CORS_HEADER_NAME, corsHeader);
+                }
+            } catch (IOException e) {
+                Log.e(TAG, "Failed to fetch the final URI", e);
+                url = "";
+            }
+            if (urlConnection != null) urlConnection.disconnect();
+        }
+        return new MediaUrlResolver.Result(url, relevantHeaders);
+    }
+
+    @Override
+    protected void onPostExecute(MediaUrlResolver.Result result) {
+        String url = result.getUri();
+        Uri uri = "".equals(url) ? Uri.EMPTY : Uri.parse(url);
+        mDelegate.setUri(uri, result.getRelevantHeaders());
+    }
+
+    private String sanitizeUrl(String unsafeUrl) {
+        URL url;
+        URI uri;
+        try {
+            url = new URL(unsafeUrl);
+            uri = new URI(url.getProtocol(), url.getUserInfo(), url.getHost(), url.getPort(),
+                    url.getPath(), url.getQuery(), url.getRef());
+            return uri.toURL().toString();
+        } catch (URISyntaxException syntaxException) {
+            Log.w(TAG, "URISyntaxException " + syntaxException);
+        } catch (MalformedURLException malformedUrlException) {
+            Log.w(TAG, "MalformedURLException " + malformedUrlException);
+        }
+        return "";
+    }
+}