Revert of https://codereview.chromium.org/115973007/

Reason for revert: Triggered Valgrind errors again.

TBR=asargent@chromium.org,tbarzic@chromium.org,stephenlin@chromium.org,nickam@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=328246

Review URL: https://codereview.chromium.org/125273006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243215 0039d316-1c4b-4281-b951-d872f2087c98

18 files changed, 45 insertions, 379 deletions

diff --git a/chrome/browser/extensions/api/image_writer_private/destroy_partitions_operation.cc b/chrome/browser/extensions/api/image_writer_private/destroy_partitions_operation.cc
deleted file mode 100644
index 23537a1..0000000
--- a/chrome/browser/extensions/api/image_writer_private/destroy_partitions_operation.cc
+++ /dev/null
@@ -1,51 +0,0 @@
-// Copyright 2014 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.
-
-#include "base/file_util.h"
-#include "chrome/browser/extensions/api/image_writer_private/destroy_partitions_operation.h"
-#include "chrome/browser/extensions/api/image_writer_private/error_messages.h"
-
-namespace extensions {
-namespace image_writer {
-
-// Number of bytes for the maximum partition table size.  By wiping this many
-// bytes we can essentially guarantee the header and associated information will
-// be wiped. See http://crbug.com/328246 for more information.
-const int kPartitionTableSize = 1 * 1024;
-
-DestroyPartitionsOperation::DestroyPartitionsOperation(
-    base::WeakPtr<OperationManager> manager,
-    const ExtensionId& extension_id,
-    const std::string& storage_unit_id)
-    : Operation(manager, extension_id, storage_unit_id) {
-  verify_write_ = false;
-}
-
-DestroyPartitionsOperation::~DestroyPartitionsOperation() {}
-
-void DestroyPartitionsOperation::Start() {
-  if (!temp_dir_.CreateUniqueTempDir()) {
-    Error(error::kTempDirError);
-    return;
-  }
-
-  if (!base::CreateTemporaryFileInDir(temp_dir_.path(), &image_path_)) {
-    Error(error::kTempFileError);
-    return;
-  }
-
-  scoped_ptr<char[]> buffer(new char[kPartitionTableSize]);
-  memset(buffer.get(), 0, kPartitionTableSize);
-
-  if (file_util::WriteFile(image_path_, buffer.get(), kPartitionTableSize) !=
-      kPartitionTableSize) {
-    Error(error::kTempFileError);
-    return;
-  }
-
-  WriteStart();
-}
-
-}  // namespace image_writer
-}  // namespace extensions
diff --git a/chrome/browser/extensions/api/image_writer_private/destroy_partitions_operation.h b/chrome/browser/extensions/api/image_writer_private/destroy_partitions_operation.h
deleted file mode 100644
index 62b36d4..0000000
--- a/chrome/browser/extensions/api/image_writer_private/destroy_partitions_operation.h
+++ /dev/null
@@ -1,33 +0,0 @@
-// Copyright 2014 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.
-
-#ifndef CHROME_BROWSER_EXTENSIONS_API_IMAGE_WRITER_PRIVATE_DESTROY_PARTITIONS_OPERATION_H_
-#define CHROME_BROWSER_EXTENSIONS_API_IMAGE_WRITER_PRIVATE_DESTROY_PARTITIONS_OPERATION_H_
-
-#include "base/files/scoped_temp_dir.h"
-#include "chrome/browser/extensions/api/image_writer_private/operation.h"
-
-namespace extensions {
-namespace image_writer {
-
-extern const int kPartitionTableSize;
-
-// Encapsulates an operation for destroying partitions.  This is achieved by
-// creating a dummy blank image which is then burned to the disk.
-class DestroyPartitionsOperation : public Operation {
- public:
-  DestroyPartitionsOperation(base::WeakPtr<OperationManager> manager,
-                             const ExtensionId& extension_id,
-                             const std::string& storage_unit_id);
-  virtual void Start() OVERRIDE;
-
- private:
-  virtual ~DestroyPartitionsOperation();
-  base::ScopedTempDir temp_dir_;
-};
-
-}  // namespace image_writer
-}  // namespace extensions
-
-#endif  // CHROME_BROWSER_EXTENSIONS_API_IMAGE_WRITER_PRIVATE_DESTROY_PARTITIONS_OPERATION_H_
diff --git a/chrome/browser/extensions/api/image_writer_private/destroy_partitions_operation_unittest.cc b/chrome/browser/extensions/api/image_writer_private/destroy_partitions_operation_unittest.cc
deleted file mode 100644
index 2b0fb93d..0000000
--- a/chrome/browser/extensions/api/image_writer_private/destroy_partitions_operation_unittest.cc
+++ /dev/null
@@ -1,66 +0,0 @@
-// Copyright 2014 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.
-
-#include "base/run_loop.h"
-#include "chrome/browser/extensions/api/image_writer_private/destroy_partitions_operation.h"
-#include "chrome/browser/extensions/api/image_writer_private/error_messages.h"
-#include "chrome/browser/extensions/api/image_writer_private/test_utils.h"
-
-namespace extensions {
-namespace image_writer {
-
-using testing::_;
-using testing::AnyNumber;
-
-namespace {
-
-class ImageWriterDestroyPartitionsOperationTest
-    : public ImageWriterUnitTestBase {
-};
-
-// Tests that the DestroyPartitionsOperation can successfully zero the first
-// kPartitionTableSize bytes of an image.
-TEST_F(ImageWriterDestroyPartitionsOperationTest, DestroyPartitions) {
-  MockOperationManager manager;
-  base::RunLoop loop;
-
-  scoped_refptr<DestroyPartitionsOperation> operation(
-      new DestroyPartitionsOperation(manager.AsWeakPtr(),
-                                     kDummyExtensionId,
-                                     test_device_path_.AsUTF8Unsafe()));
-
-#if defined(OS_LINUX) || defined(OS_CHROMEOS)
-  EXPECT_CALL(manager, OnProgress(kDummyExtensionId, _, _)).Times(0);
-  EXPECT_CALL(manager, OnProgress(kDummyExtensionId,
-                                  image_writer_api::STAGE_WRITE,
-                                  _)).Times(AnyNumber());
-  EXPECT_CALL(manager, OnComplete(kDummyExtensionId)).Times(1);
-  EXPECT_CALL(manager, OnError(kDummyExtensionId, _, _, _)).Times(0);
-#else
-  EXPECT_CALL(manager, OnProgress(kDummyExtensionId, _, _)).Times(0);
-  EXPECT_CALL(manager, OnComplete(kDummyExtensionId)).Times(0);
-  EXPECT_CALL(manager, OnError(kDummyExtensionId,
-                               _,
-                               _,
-                               error::kUnsupportedOperation)).Times(1);
-#endif
-
-  operation->Start();
-
-  loop.RunUntilIdle();
-
-#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
-  scoped_ptr<char[]> image_data(new char[kPartitionTableSize]);
-  scoped_ptr<char[]> zeroes(new char[kPartitionTableSize]);
-  memset(zeroes.get(), 0, kPartitionTableSize);
-  ASSERT_EQ(kPartitionTableSize, base::ReadFile(test_device_path_,
-                                                image_data.get(),
-                                                kPartitionTableSize));
-  EXPECT_EQ(0, memcmp(image_data.get(), zeroes.get(), kPartitionTableSize));
-#endif
-}
-
-} // namespace
-} // namespace image_writer
-} // namespace extensions
diff --git a/chrome/browser/extensions/api/image_writer_private/image_writer_private_api.cc b/chrome/browser/extensions/api/image_writer_private/image_writer_private_api.cc
index 3d7fd42..fffd1ac 100644
--- a/chrome/browser/extensions/api/image_writer_private/image_writer_private_api.cc
+++ b/chrome/browser/extensions/api/image_writer_private/image_writer_private_api.cc
@@ -151,25 +151,10 @@ bool ImageWriterPrivateDestroyPartitionsFunction::RunImpl() {
       image_writer_api::DestroyPartitions::Params::Create(*args_));
   EXTENSION_FUNCTION_VALIDATE(params.get());
 
-  image_writer::OperationManager::Get(GetProfile())->DestroyPartitions(
-      extension_id(),
-      params->storage_unit_id,
-      base::Bind(
-          &ImageWriterPrivateDestroyPartitionsFunction::OnDestroyComplete,
-          this));
+  SendResponse(true);
   return true;
 }
 
-void ImageWriterPrivateDestroyPartitionsFunction::OnDestroyComplete(
-    bool success,
-    const std::string& error) {
-  if (!success) {
-    error_ = error;
-  }
-
-  SendResponse(success);
-}
-
 ImageWriterPrivateListRemovableStorageDevicesFunction::
   ImageWriterPrivateListRemovableStorageDevicesFunction() {
 }
diff --git a/chrome/browser/extensions/api/image_writer_private/image_writer_private_api.h b/chrome/browser/extensions/api/image_writer_private/image_writer_private_api.h
index 9cccd0fc..4789d18 100644
--- a/chrome/browser/extensions/api/image_writer_private/image_writer_private_api.h
+++ b/chrome/browser/extensions/api/image_writer_private/image_writer_private_api.h
@@ -59,7 +59,6 @@ class ImageWriterPrivateDestroyPartitionsFunction
  private:
   virtual ~ImageWriterPrivateDestroyPartitionsFunction();
   virtual bool RunImpl() OVERRIDE;
-  void OnDestroyComplete(bool success, const std::string& error);
 };
 
 class ImageWriterPrivateListRemovableStorageDevicesFunction
diff --git a/chrome/browser/extensions/api/image_writer_private/operation.cc b/chrome/browser/extensions/api/image_writer_private/operation.cc
index 4a57c7d..743f797 100644
--- a/chrome/browser/extensions/api/image_writer_private/operation.cc
+++ b/chrome/browser/extensions/api/image_writer_private/operation.cc
@@ -32,7 +32,6 @@ Operation::Operation(base::WeakPtr<OperationManager> manager,
     : manager_(manager),
       extension_id_(extension_id),
       storage_unit_id_(storage_unit_id),
-      verify_write_(true),
       stage_(image_writer_api::STAGE_UNKNOWN),
       progress_(0) {
 }
diff --git a/chrome/browser/extensions/api/image_writer_private/operation.h b/chrome/browser/extensions/api/image_writer_private/operation.h
index ce62f65..7e45fe1 100644
--- a/chrome/browser/extensions/api/image_writer_private/operation.h
+++ b/chrome/browser/extensions/api/image_writer_private/operation.h
@@ -110,9 +110,6 @@ class Operation
   base::FilePath image_path_;
   const std::string storage_unit_id_;
 
-  // Whether or not to run the final verification step.
-  bool verify_write_;
-
  private:
   friend class base::RefCountedThreadSafe<Operation>;
 
diff --git a/chrome/browser/extensions/api/image_writer_private/operation_linux.cc b/chrome/browser/extensions/api/image_writer_private/operation_linux.cc
index df34834b..798dea3 100644
--- a/chrome/browser/extensions/api/image_writer_private/operation_linux.cc
+++ b/chrome/browser/extensions/api/image_writer_private/operation_linux.cc
@@ -138,15 +138,11 @@ void Operation::WriteComplete() {
   DVLOG(2) << "Completed write of " << image_path_.value();
   SetProgress(kProgressComplete);
 
-  if (verify_write_) {
-    BrowserThread::PostTask(BrowserThread::FILE,
-                            FROM_HERE,
-                            base::Bind(&Operation::VerifyWriteStart, this));
-  } else {
-    BrowserThread::PostTask(BrowserThread::FILE,
-                            FROM_HERE,
-                            base::Bind(&Operation::Finish, this));
-  }
+  BrowserThread::PostTask(
+    BrowserThread::FILE,
+    FROM_HERE,
+    base::Bind(&Operation::VerifyWriteStart,
+               this));
 }
 
 void Operation::VerifyWriteStart() {
diff --git a/chrome/browser/extensions/api/image_writer_private/operation_manager.cc b/chrome/browser/extensions/api/image_writer_private/operation_manager.cc
index 2b525e5..b1b1c44 100644
--- a/chrome/browser/extensions/api/image_writer_private/operation_manager.cc
+++ b/chrome/browser/extensions/api/image_writer_private/operation_manager.cc
@@ -5,7 +5,6 @@
 #include "base/lazy_instance.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_notification_types.h"
-#include "chrome/browser/extensions/api/image_writer_private/destroy_partitions_operation.h"
 #include "chrome/browser/extensions/api/image_writer_private/error_messages.h"
 #include "chrome/browser/extensions/api/image_writer_private/operation.h"
 #include "chrome/browser/extensions/api/image_writer_private/operation_manager.h"
@@ -64,6 +63,7 @@ void OperationManager::StartWriteFromUrl(
     bool saveImageAsDownload,
     const std::string& storage_unit_id,
     const Operation::StartWriteCallback& callback) {
+
   OperationMap::iterator existing_operation = operations_.find(extension_id);
 
   if (existing_operation != operations_.end()) {
@@ -78,10 +78,14 @@ void OperationManager::StartWriteFromUrl(
                                 hash,
                                 saveImageAsDownload,
                                 storage_unit_id));
+
   operations_[extension_id] = operation;
+
   BrowserThread::PostTask(BrowserThread::FILE,
                           FROM_HERE,
-                          base::Bind(&Operation::Start, operation));
+                          base::Bind(&Operation::Start,
+                                     operation.get()));
+
   callback.Run(true, "");
 }
 
@@ -101,10 +105,14 @@ void OperationManager::StartWriteFromFile(
                                  extension_id,
                                  path,
                                  storage_unit_id));
+
   operations_[extension_id] = operation;
+
   BrowserThread::PostTask(BrowserThread::FILE,
                           FROM_HERE,
-                          base::Bind(&Operation::Start, operation));
+                          base::Bind(&Operation::Start,
+                                     operation.get()));
+
   callback.Run(true, "");
 }
 
@@ -124,27 +132,6 @@ void OperationManager::CancelWrite(
   }
 }
 
-void OperationManager::DestroyPartitions(
-    const ExtensionId& extension_id,
-    const std::string& storage_unit_id,
-    const Operation::StartWriteCallback& callback) {
-  OperationMap::iterator existing_operation = operations_.find(extension_id);
-
-  if (existing_operation != operations_.end()) {
-    return callback.Run(false, error::kOperationAlreadyInProgress);
-  }
-
-  scoped_refptr<Operation> operation(
-      new DestroyPartitionsOperation(weak_factory_.GetWeakPtr(),
-                                     extension_id,
-                                     storage_unit_id));
-  operations_[extension_id] = operation;
-  BrowserThread::PostTask(BrowserThread::FILE,
-                          FROM_HERE,
-                          base::Bind(&Operation::Start, operation));
-  callback.Run(true, "");
-}
-
 void OperationManager::OnProgress(const ExtensionId& extension_id,
                                   image_writer_api::Stage stage,
                                   int progress) {
diff --git a/chrome/browser/extensions/api/image_writer_private/operation_manager.h b/chrome/browser/extensions/api/image_writer_private/operation_manager.h
index 00489bc..56655fcb 100644
--- a/chrome/browser/extensions/api/image_writer_private/operation_manager.h
+++ b/chrome/browser/extensions/api/image_writer_private/operation_manager.h
@@ -61,11 +61,6 @@ class OperationManager
   void CancelWrite(const ExtensionId& extension_id,
                    const Operation::CancelWriteCallback& callback);
 
-  // Starts a write that removes the partition table.
-  void DestroyPartitions(const ExtensionId& extension_id,
-                         const std::string& storage_unit_id,
-                         const Operation::StartWriteCallback& callback);
-
   // Callback for progress events.
   virtual void OnProgress(const ExtensionId& extension_id,
                           image_writer_api::Stage stage,
diff --git a/chrome/browser/extensions/api/image_writer_private/operation_manager_unittest.cc b/chrome/browser/extensions/api/image_writer_private/operation_manager_unittest.cc
index 80ccfa6..ed9c3f3 100644
--- a/chrome/browser/extensions/api/image_writer_private/operation_manager_unittest.cc
+++ b/chrome/browser/extensions/api/image_writer_private/operation_manager_unittest.cc
@@ -5,8 +5,8 @@
 #include "base/command_line.h"
 #include "chrome/browser/chromeos/login/user_manager.h"
 #include "chrome/browser/extensions/api/image_writer_private/error_messages.h"
-#include "chrome/browser/extensions/api/image_writer_private/operation_manager.h"
 #include "chrome/browser/extensions/api/image_writer_private/test_utils.h"
+#include "chrome/browser/extensions/api/image_writer_private/write_from_file_operation.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/test_extension_system.h"
 #include "chrome/test/base/testing_profile.h"
@@ -25,8 +25,6 @@ using testing::Lt;
 using testing::AnyNumber;
 using testing::AtLeast;
 
-namespace {
-
 class ImageWriterOperationManagerTest
     : public ImageWriterUnitTestBase {
  public:
@@ -70,8 +68,8 @@ TEST_F(ImageWriterOperationManagerTest, WriteFromFile) {
 
   manager.StartWriteFromFile(
     kDummyExtensionId,
-    test_image_path_,
-    test_device_path_.AsUTF8Unsafe(),
+    test_image_,
+    test_device_.AsUTF8Unsafe(),
     base::Bind(&ImageWriterOperationManagerTest::StartCallback,
                base::Unretained(this)));
 
@@ -80,20 +78,5 @@ TEST_F(ImageWriterOperationManagerTest, WriteFromFile) {
   EXPECT_EQ("", start_error_);
 }
 
-TEST_F(ImageWriterOperationManagerTest, DestroyPartitions) {
-  OperationManager manager(&test_profile_);
-
-  manager.DestroyPartitions(
-      kDummyExtensionId,
-      test_device_path_.AsUTF8Unsafe(),
-      base::Bind(&ImageWriterOperationManagerTest::StartCallback,
-                 base::Unretained(this)));
-
-  EXPECT_TRUE(started_);
-  EXPECT_TRUE(start_success_);
-  EXPECT_EQ("", start_error_);
-}
-
-} // namespace
-} // namespace image_writer
-} // namespace extensions
+}  // namespace image_writer
+}  // namespace extensions
diff --git a/chrome/browser/extensions/api/image_writer_private/operation_unittest.cc b/chrome/browser/extensions/api/image_writer_private/operation_unittest.cc
index 49ccd88..0df18fb 100644
--- a/chrome/browser/extensions/api/image_writer_private/operation_unittest.cc
+++ b/chrome/browser/extensions/api/image_writer_private/operation_unittest.cc
@@ -8,7 +8,6 @@
 
 namespace extensions {
 namespace image_writer {
-namespace {
 
 class ImageWriterOperationTest : public ImageWriterUnitTestBase {
 };
@@ -26,15 +25,13 @@ class DummyOperation : public Operation {
 
 TEST_F(ImageWriterOperationTest, Create) {
   MockOperationManager manager;
-  scoped_refptr<Operation> op(
-      new DummyOperation(manager.AsWeakPtr(),
-                         kDummyExtensionId,
-                         test_device_path_.AsUTF8Unsafe()));
+  scoped_refptr<Operation> op(new DummyOperation(manager.AsWeakPtr(),
+                                                 kDummyExtensionId,
+                                                 test_device_.AsUTF8Unsafe()));
 
   EXPECT_EQ(0, op->GetProgress());
   EXPECT_EQ(image_writer_api::STAGE_UNKNOWN, op->GetStage());
 }
 
-}  // namespace
 }  // namespace image_writer
 }  // namespace extensions
diff --git a/chrome/browser/extensions/api/image_writer_private/test_utils.cc b/chrome/browser/extensions/api/image_writer_private/test_utils.cc
index caef818c..651ce0a 100644
--- a/chrome/browser/extensions/api/image_writer_private/test_utils.cc
+++ b/chrome/browser/extensions/api/image_writer_private/test_utils.cc
@@ -4,119 +4,26 @@
 
 #include "chrome/browser/extensions/api/image_writer_private/test_utils.h"
 
-#if defined(OS_CHROMEOS)
-#include "chromeos/dbus/dbus_thread_manager.h"
-#include "chromeos/dbus/fake_dbus_thread_manager.h"
-#include "chromeos/dbus/fake_image_burner_client.h"
-#endif
-
 namespace extensions {
 namespace image_writer {
 
-#if defined(OS_CHROMEOS)
-namespace {
-
-class ImageWriterFakeImageBurnerClient
-    : public chromeos::FakeImageBurnerClient {
- public:
-  ImageWriterFakeImageBurnerClient() {}
-  virtual ~ImageWriterFakeImageBurnerClient() {}
-
-  virtual void SetEventHandlers(
-      const BurnFinishedHandler& burn_finished_handler,
-      const BurnProgressUpdateHandler& burn_progress_update_handler) OVERRIDE {
-    burn_finished_handler_ = burn_finished_handler;
-    burn_progress_update_handler_ = burn_progress_update_handler;
-  }
-
-  virtual void BurnImage(const std::string& from_path,
-                         const std::string& to_path,
-                         const ErrorCallback& error_callback) OVERRIDE {
-    base::MessageLoop::current()->PostTask(FROM_HERE,
-        base::Bind(burn_progress_update_handler_, to_path, 0, 100));
-    base::MessageLoop::current()->PostTask(FROM_HERE,
-        base::Bind(burn_progress_update_handler_, to_path, 50, 100));
-    base::MessageLoop::current()->PostTask(FROM_HERE,
-        base::Bind(burn_progress_update_handler_, to_path, 100, 100));
-    base::MessageLoop::current()->PostTask(FROM_HERE,
-        base::Bind(burn_finished_handler_, to_path, true, ""));
-  }
-
- private:
-  BurnFinishedHandler burn_finished_handler_;
-  BurnProgressUpdateHandler burn_progress_update_handler_;
-
-};
-
-} // namespace
-#endif
-
 MockOperationManager::MockOperationManager()
-    : OperationManager(NULL) {}
-
-MockOperationManager::~MockOperationManager() {}
-
-ImageWriterUnitTestBase::ImageWriterUnitTestBase() {}
-ImageWriterUnitTestBase::~ImageWriterUnitTestBase() {}
-
-void ImageWriterUnitTestBase::SetUp() {
-  testing::Test::SetUp();
-  ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
-
-  ASSERT_TRUE(base::CreateTemporaryFileInDir(temp_dir_.path(),
-                                             &test_image_path_));
-  ASSERT_TRUE(base::CreateTemporaryFileInDir(temp_dir_.path(),
-                                             &test_device_path_));
-
-  ASSERT_TRUE(FillFile(test_image_path_, kImagePattern, kTestFileSize));
-  ASSERT_TRUE(FillFile(test_device_path_, kDevicePattern, kTestFileSize));
-
-#if defined(OS_CHROMEOS)
-  if (!chromeos::DBusThreadManager::IsInitialized()) {
-    chromeos::FakeDBusThreadManager* fake_dbus_thread_manager =
-        new chromeos::FakeDBusThreadManager;
-    scoped_ptr<chromeos::ImageBurnerClient>
-        image_burner_fake(new ImageWriterFakeImageBurnerClient());
-    fake_dbus_thread_manager->SetImageBurnerClient(image_burner_fake.Pass());
-    chromeos::DBusThreadManager::InitializeForTesting(fake_dbus_thread_manager);
-  }
-#endif
+    : OperationManager(NULL) {
 }
 
-void ImageWriterUnitTestBase::TearDown() {}
-
-bool ImageWriterUnitTestBase::CompareImageAndDevice() {
-  scoped_ptr<char[]> image_buffer(new char[kTestFileSize]);
-  scoped_ptr<char[]> device_buffer(new char[kTestFileSize]);
-
-  while (true) {
-    int image_bytes_read = ReadFile(test_image_path_,
-                                    image_buffer.get(),
-                                    kTestFileSize);
-    int device_bytes_read = ReadFile(test_device_path_,
-                                     device_buffer.get(),
-                                     kTestFileSize);
-
-    if (image_bytes_read != device_bytes_read)
-      return false;
-
-    if (image_bytes_read == 0)
-      return true;
+MockOperationManager::~MockOperationManager() {
+}
 
-    if (memcmp(image_buffer.get(), device_buffer.get(), image_bytes_read) != 0)
-      return false;
-  }
+void ImageWriterUnitTestBase::SetUp() {
+  ASSERT_TRUE(base::CreateTemporaryFile(&test_image_));
+  ASSERT_TRUE(base::CreateTemporaryFile(&test_device_));
 
-  return false;
+  ASSERT_EQ(32, file_util::WriteFile(test_image_, kTestData, 32));
 }
 
-bool ImageWriterUnitTestBase::FillFile(const base::FilePath& file,
-                                       const int pattern,
-                                       const int length) {
-  scoped_ptr<char[]> buffer(new char[length]);
-  memset(buffer.get(), pattern, length);
-
-  return file_util::WriteFile(file, buffer.get(), length) == length;
+void ImageWriterUnitTestBase::TearDown() {
+  base::DeleteFile(test_image_, false);
+  base::DeleteFile(test_device_, false);
 }
 
 }  // namespace image_writer
diff --git a/chrome/browser/extensions/api/image_writer_private/test_utils.h b/chrome/browser/extensions/api/image_writer_private/test_utils.h
index b290e88..88ccf49 100644
--- a/chrome/browser/extensions/api/image_writer_private/test_utils.h
+++ b/chrome/browser/extensions/api/image_writer_private/test_utils.h
@@ -6,7 +6,6 @@
 #define CHROME_BROWSER_EXTENSIONS_API_IMAGE_WRITER_PRIVATE_TEST_UTILS_H_
 
 #include "base/file_util.h"
-#include "base/files/scoped_temp_dir.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "chrome/browser/extensions/api/image_writer_private/operation_manager.h"
@@ -18,16 +17,8 @@ namespace extensions {
 namespace image_writer {
 
 const char kDummyExtensionId[] = "DummyExtension";
+const char kTestData[] = "This is some test data, padded.  ";
 
-// Default file size to use in tests.  Currently 32kB.
-const int kTestFileSize = 32 * 1024;
-// Pattern to use in the image file.
-const int kImagePattern = 0x55555555; // 01010101
-// Pattern to use in the device file.
-const int kDevicePattern = 0xAAAAAAAA; // 10101010
-
-// A mock around the operation manager for tracking callbacks.  Note that there
-// are non-virtual methods on this class that should not be called in tests.
 class MockOperationManager : public OperationManager {
  public:
   MockOperationManager();
@@ -46,32 +37,15 @@ class MockOperationManager : public OperationManager {
                              const std::string& error_message));
 };
 
-// Base class for unit tests that manages creating image and device files.
 class ImageWriterUnitTestBase : public testing::Test {
  public:
-  ImageWriterUnitTestBase();
-  virtual ~ImageWriterUnitTestBase();
-
- protected:
   virtual void SetUp() OVERRIDE;
 
   virtual void TearDown() OVERRIDE;
 
-  // Compare the image and device files, returning true if they are the same,
-  // false if different.
-  bool CompareImageAndDevice();
-
-  base::ScopedTempDir temp_dir_;
-  base::FilePath test_image_path_;
-  base::FilePath test_device_path_;
-
+  base::FilePath test_image_;
+  base::FilePath test_device_;
  private:
-  // Fills |file| with |length| bytes of |pattern|, overwriting any existing
-  // data.
-  bool FillFile(const base::FilePath& file,
-                const int pattern,
-                const int length);
-
   content::TestBrowserThreadBundle thread_bundle_;
 };
 
diff --git a/chrome/browser/extensions/api/image_writer_private/write_from_file_operation_unittest.cc b/chrome/browser/extensions/api/image_writer_private/write_from_file_operation_unittest.cc
index 223d731..c24484d 100644
--- a/chrome/browser/extensions/api/image_writer_private/write_from_file_operation_unittest.cc
+++ b/chrome/browser/extensions/api/image_writer_private/write_from_file_operation_unittest.cc
@@ -23,10 +23,10 @@ TEST_F(ImageWriterFromFileTest, InvalidFile) {
   scoped_refptr<WriteFromFileOperation> op = new WriteFromFileOperation(
     manager.AsWeakPtr(),
     kDummyExtensionId,
-    test_image_path_,
-    test_device_path_.AsUTF8Unsafe());
+    test_image_,
+    test_device_.AsUTF8Unsafe());
 
-  base::DeleteFile(test_image_path_, false);
+  base::DeleteFile(test_image_, false);
 
   EXPECT_CALL(manager, OnProgress(kDummyExtensionId, _, _)).Times(0);
   EXPECT_CALL(manager, OnComplete(kDummyExtensionId)).Times(0);
diff --git a/chrome/chrome_browser_extensions.gypi b/chrome/chrome_browser_extensions.gypi
index 3d530d4..d1abc5f 100644
--- a/chrome/chrome_browser_extensions.gypi
+++ b/chrome/chrome_browser_extensions.gypi
@@ -319,11 +319,9 @@
         'browser/extensions/api/idltest/idltest_api.h',
         'browser/extensions/api/image_writer_private/error_messages.cc',
         'browser/extensions/api/image_writer_private/error_messages.h',
-        'browser/extensions/api/image_writer_private/destroy_partitions_operation.cc',
-        'browser/extensions/api/image_writer_private/destroy_partitions_operation.h',
         'browser/extensions/api/image_writer_private/operation.cc',
-        'browser/extensions/api/image_writer_private/operation.h',
         'browser/extensions/api/image_writer_private/operation_chromeos.cc',
+        'browser/extensions/api/image_writer_private/operation.h',
         'browser/extensions/api/image_writer_private/operation_linux.cc',
         'browser/extensions/api/image_writer_private/operation_mac.cc',
         'browser/extensions/api/image_writer_private/operation_manager.cc',
diff --git a/chrome/chrome_tests_unit.gypi b/chrome/chrome_tests_unit.gypi
index 640acbe..a0d8efa 100644
--- a/chrome/chrome_tests_unit.gypi
+++ b/chrome/chrome_tests_unit.gypi
@@ -841,7 +841,6 @@
         'browser/extensions/api/identity/gaia_web_auth_flow_unittest.cc',
         'browser/extensions/api/identity/identity_mint_queue_unittest.cc',
         'browser/extensions/api/idle/idle_api_unittest.cc',
-        'browser/extensions/api/image_writer_private/destroy_partitions_operation_unittest.cc',
         'browser/extensions/api/image_writer_private/operation_manager_unittest.cc',
         'browser/extensions/api/image_writer_private/operation_unittest.cc',
         'browser/extensions/api/image_writer_private/test_utils.cc',
diff --git a/chrome/common/extensions/api/image_writer_private.idl b/chrome/common/extensions/api/image_writer_private.idl
index 9fcd3d2..e46eefe 100644
--- a/chrome/common/extensions/api/image_writer_private.idl
+++ b/chrome/common/extensions/api/image_writer_private.idl
@@ -101,11 +101,11 @@
 
     // Destroys the partition table of a disk, effectively erasing it.  This is
     // a fairly quick operation and so it does not have complex stages or
-    // progress information, just a write phase.
+    // progress information.  However, it can fail and call the callback with
+    // an error.
     //
     // |storageUnitId|: The identifier of the storage unit to wipe
-    // |callback|: A callback that triggers when the operation has been
-    // successfully started.
+    // |callback|: A callback which is called when the operation is complete.
     static void destroyPartitions(DOMString storageUnitId,
                                   DestroyPartitionsCallback callback);