Introduce background Download process to android

content/public/android/java/src/org/chromium/content/app/ChildProcessService.java

 // Copyright 2012 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.content.app;
 
 import android.app.Service;
 import android.content.Context;
 import android.content.Intent;
 import android.graphics.SurfaceTexture;
 import android.os.Bundle;
 import android.os.IBinder;
 import android.os.Parcelable;
 import android.os.Process;
 import android.os.RemoteException;
 import android.view.Surface;
 
 import org.chromium.base.BaseSwitches;
 import org.chromium.base.CommandLine;
 import org.chromium.base.ContextUtils;
 import org.chromium.base.Log;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
 import org.chromium.base.annotations.SuppressFBWarnings;
 import org.chromium.base.library_loader.LibraryLoader;
 import org.chromium.base.library_loader.LibraryProcessType;
 import org.chromium.base.library_loader.Linker;
 import org.chromium.base.library_loader.ProcessInitException;
 import org.chromium.content.browser.ChildProcessConstants;
-import org.chromium.content.browser.ChildProcessLauncher;
 import org.chromium.content.browser.FileDescriptorInfo;
+import org.chromium.content.common.ContentSwitches;
 import org.chromium.content.common.IChildProcessCallback;
 import org.chromium.content.common.IChildProcessService;
 import org.chromium.content.common.SurfaceWrapper;
 
 import java.util.concurrent.Semaphore;
 import java.util.concurrent.atomic.AtomicReference;
 
 /**
  * This is the base class for child services; the [Non]SandboxedProcessService0, 1.. etc
  * subclasses provide the concrete service entry points, to enable the browser to connect
  * to more than one distinct process (i.e. one process per service number, up to limit of N).
  * The embedding application must declare these service instances in the application section
  * of its AndroidManifest.xml, for example with N entries of the form:-
  *     <service android:name="org.chromium.content.app.[Non]SandboxedProcessServiceX"
  *              android:process=":[non]sandboxed_processX" />
  * for X in 0...N-1 (where N is {@link ChildProcessLauncher#MAX_REGISTERED_SERVICES})
  */
 @JNINamespace("content")
 @SuppressWarnings("SynchronizeOnNonFinalField")
 public class ChildProcessService extends Service {
     private static final String MAIN_THREAD_NAME = "ChildProcessMain";
     private static final String TAG = "ChildProcessService";
+    protected static final FileDescriptorInfo[] EMPTY_FILE_DESCRIPTOR_INFO = {};
     private IChildProcessCallback mCallback;
 
     // This is the native "Main" thread for the renderer / utility process.
     private Thread mMainThread;
     // Parameters received via IPC, only accessed while holding the mMainThread monitor.
     private String[] mCommandLineParams;
     private int mCpuCount;
     private long mCpuFeatures;
     // File descriptors that should be registered natively.
     private FileDescriptorInfo[] mFdInfos;
@@ skipping 218 matching lines @@
             mCpuFeatures = bundle.getLong(ChildProcessConstants.EXTRA_CPU_FEATURES);
             assert mCpuCount > 0;
             Parcelable[] fdInfosAsParcelable =
                     bundle.getParcelableArray(ChildProcessConstants.EXTRA_FILES);
             if (fdInfosAsParcelable != null) {
                 // For why this arraycopy is necessary:
                 // http://stackoverflow.com/questions/8745893/i-dont-get-why-this-classcastexception-occurs
                 mFdInfos = new FileDescriptorInfo[fdInfosAsParcelable.length];
                 System.arraycopy(fdInfosAsParcelable, 0, mFdInfos, 0, fdInfosAsParcelable.length);
             } else {
-                // TODO(qinmin): On earlier androird versions, a started service running in another
-                // process can get killed after Chrome is killed. To work around this issue, client
-                // will never bind to the service. As a result, the file descriptors needs to be
-                // passed through an intent when starting the service.
+                String processType = ContentSwitches.getSwitchValue(
+                        mCommandLineParams, ContentSwitches.SWITCH_PROCESS_TYPE);
+                assert ContentSwitches.SWITCH_DOWNLOAD_PROCESS.equals(processType);
+                mFdInfos = EMPTY_FILE_DESCRIPTOR_INFO;
             }
             Bundle sharedRelros = bundle.getBundle(Linker.EXTRA_LINKER_SHARED_RELROS);
             if (sharedRelros != null) {
                 getLinker().useSharedRelros(sharedRelros);
                 sharedRelros = null;
             }
             mMainThread.notifyAll();
         }
     }
 
@@ skipping 123 matching lines @@
     private static native void nativeInitChildProcess(
             ChildProcessService service, int cpuCount, long cpuFeatures);
 
     /**
      * Force the child process to exit.
      */
     private static native void nativeExitChildProcess();
 
     private native void nativeShutdownMainThread();
 }