Added unpacking step

chrome/installer/mac/app/Unpacker.m

Index: chrome/installer/mac/app/Unpacker.m
diff --git a/chrome/installer/mac/app/Unpacker.m b/chrome/installer/mac/app/Unpacker.m
new file mode 100644
index 0000000000000000000000000000000000000000..f3b9072870cc8256883c731a0ba5ee083df283e2
--- /dev/null
+++ b/chrome/installer/mac/app/Unpacker.m
@@ -0,0 +1,167 @@
+// Copyright 2016 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.
+
+#import "Unpacker.h"
+
+#import <AppKit/AppKit.h>
+#include <DiskArbitration/DiskArbitration.h>
+#include <dispatch/dispatch.h>
+
+#import "Downloader.h"
+
+@interface Unpacker () {
+  NSURL* temporaryDirectoryURL_;
+  NSString* mountPath_;
+
+  NSTask* __weak mountTask_;
+
+  DASessionRef session_;
+  dispatch_queue_t unpack_dq_;
+}
+- (void)didFinishEjectingDisk:(DADiskRef)disk
+                withDissenter:(DADissenterRef)dissenter;
+@end
+
+static void eject_callback(DADiskRef disk,
+                           DADissenterRef dissenter,
+                           void* context) {
+  Unpacker* unpacker = (__bridge_transfer Unpacker*)context;
+  [unpacker didFinishEjectingDisk:disk withDissenter:dissenter];
+}
+
+static void unmount_callback(DADiskRef disk,
+                             DADissenterRef dissenter,
+                             void* context) {
+  if (dissenter) {
+    Unpacker* unpacker = (__bridge Unpacker*)context;
+    [unpacker didFinishEjectingDisk:disk withDissenter:dissenter];
+  } else {
+    DADiskEject(disk, kDADiskEjectOptionDefault, eject_callback, context);
+  }
+}
+
+@implementation Unpacker
+
+@synthesize delegate = delegate_;
+@synthesize appPath = appPath_;
+
+- (void)cleanUp {
+  [mountTask_ terminate];
+  // It's not the end of the world if this temporary directory is not removed
+  // here. It will be deleted when the operating system itself decides to
+  // anyway.
+  [[NSFileManager defaultManager] removeItemAtURL:temporaryDirectoryURL_
+                                            error:nil];
+  [[NSNotificationCenter defaultCenter] removeObserver:self];
+}
+
+// TODO: the failure delegate methods need to be revised to be more meaningfully
+// deal with the errors (pipe in stderr / stdout)
+- (void)mountDMGFromURL:(NSURL*)fileURL {
+  NSError* error = nil;
+  temporaryDirectoryURL_ = [[NSFileManager defaultManager]
+        URLForDirectory:NSItemReplacementDirectory
+               inDomain:NSUserDomainMask
+      appropriateForURL:[NSURL fileURLWithPath:@"/" isDirectory:YES]
+                 create:YES
+                  error:&error];
+  if (error) {
+    [delegate_ unpacker:self onMountFailure:error];
+    return;
+  }
+
+  NSURL* temporaryDiskImageURL =
+      [temporaryDirectoryURL_ URLByAppendingPathComponent:@"GoogleChrome.dmg"];
+  mountPath_ = [[temporaryDirectoryURL_ URLByAppendingPathComponent:@"mnt"
+                                                        isDirectory:YES] path];
+  [[NSFileManager defaultManager] createDirectoryAtPath:mountPath_
+                            withIntermediateDirectories:YES
+                                             attributes:nil
+                                                  error:&error];
+  if (error) {
+    [delegate_ unpacker:self onMountFailure:error];
+    return;
+  }
+
+  // If the user closes the app at any time, we make sure that the cleanUp
+  // function deletes the temporary folder we just created.
+  [[NSNotificationCenter defaultCenter]
+      addObserver:self
+         selector:@selector(cleanUp)
+             name:NSApplicationWillTerminateNotification
+           object:nil];
+
+  [[NSFileManager defaultManager] moveItemAtURL:fileURL
+                                          toURL:temporaryDiskImageURL
+                                          error:nil];
+
+  NSString* path = @"/usr/bin/hdiutil";
+  NSArray* args = @[
+    @"attach", temporaryDiskImageURL, @"-nobrowse", @"-noverify",
+    @"-mountpoint", mountPath_
+  ];
+
+  NSTask* mountTask = [[NSTask alloc] init];
+  mountTask.launchPath = path;
+  mountTask.arguments = args;
+  mountTask.terminationHandler = ^void(NSTask* task) {
+    NSError* error = nil;
+    NSString* diskAppPath =
+        [NSString pathWithComponents:@[ mountPath_, @"Google Chrome.app" ]];
+    NSString* tempAppPath = [[temporaryDirectoryURL_
+        URLByAppendingPathComponent:@"Google Chrome.app"] path];
+    [[NSFileManager defaultManager] copyItemAtPath:diskAppPath
+                                            toPath:tempAppPath
+                                             error:&error];
+    if (error) {
+      [delegate_ unpacker:self onMountFailure:error];
+    } else {
+      [delegate_ unpacker:self onMountSuccess:tempAppPath];
+    }
+  };
+  mountTask_ = mountTask;
+  [mountTask launch];
+}
+
+- (void)unmountDMG {
+  session_ = DASessionCreate(nil);
+  unpack_dq_ =
+      dispatch_queue_create("com.google.chrome.unpack", DISPATCH_QUEUE_SERIAL);
+  DASessionSetDispatchQueue(session_, unpack_dq_);
+  DADiskRef child_disk = DADiskCreateFromVolumePath(
+      nil, session_,
+      (__bridge CFURLRef)[NSURL fileURLWithPath:mountPath_ isDirectory:YES]);
+  DADiskRef whole_disk = DADiskCopyWholeDisk(child_disk);
+
+  DADiskUnmount(whole_disk,
+                kDADiskUnmountOptionWhole | kDADiskUnmountOptionForce,
+                unmount_callback, (__bridge_retained void*)self);
+
+  CFRelease(whole_disk);
+  CFRelease(child_disk);
+}
+
+- (void)didFinishEjectingDisk:(DADiskRef)disk
+                withDissenter:(DADissenterRef)dissenter {
+  DASessionSetDispatchQueue(session_, NULL);
+  dispatch_release(unpack_dq_);
+  CFRelease(session_);
+  NSError* error = nil;
+  if (dissenter) {
+    DAReturn status = DADissenterGetStatus(dissenter);
+    error = [NSError
+        errorWithDomain:@"ChromeErrorDomain"
+                   code:err_get_code(status)
+               userInfo:@{
+                 NSLocalizedDescriptionKey :
+                     (__bridge NSString*)DADissenterGetStatusString(dissenter)
+               }];
+    [delegate_ unpacker:self onUnmountFailure:error];
+  } else {
+    [self cleanUp];
+    [delegate_ unpacker:self onUnmountSuccess:mountPath_];
+  }
+}
+
+@end