Add fake StorageFileStatics for testing

Adding a class to represent the Windows StorageFileStatics class within
tests, as well as basic unit tests to validate the test class behaviors.
The class behaves similarly to the Windows equivalent, except it
includes gtest validations for expected usage, schedules all async
operations through a ThreadTaskRunner, and does not implement methods
that fall outside the expected usage.

Bug: 1035527
Change-Id: Ia3439718cb02773e7a6c6835adcdbc807f47a383
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2491050Reviewed-by: Eric Willigers <ericwilligers@chromium.org>
Commit-Queue: Hoch Hochkeppel <mhochk@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#819696}

chrome/browser/webshare/win/fake_storage_file_statics.cc

+// Copyright 2020 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 "chrome/browser/webshare/win/fake_storage_file_statics.h"
+
+#include <windows.foundation.h>
+#include <windows.storage.streams.h>
+#include <wrl/module.h>
+
+#include <memory>
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/test/bind_test_util.h"
+#include "base/test/fake_iasync_operation_win.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "base/win/scoped_hstring.h"
+#include "chrome/browser/webshare/win/fake_random_access_stream.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using ABI::Windows::Foundation::DateTime;
+using ABI::Windows::Foundation::IAsyncAction;
+using ABI::Windows::Foundation::IAsyncOperation;
+using ABI::Windows::Foundation::IUriRuntimeClass;
+using ABI::Windows::Storage::FileAccessMode;
+using ABI::Windows::Storage::FileAttributes;
+using ABI::Windows::Storage::IStorageFile;
+using ABI::Windows::Storage::IStorageFolder;
+using ABI::Windows::Storage::IStorageItem;
+using ABI::Windows::Storage::IStreamedFileDataRequestedHandler;
+using ABI::Windows::Storage::NameCollisionOption;
+using ABI::Windows::Storage::StorageDeleteOption;
+using ABI::Windows::Storage::StorageFile;
+using ABI::Windows::Storage::StorageItemTypes;
+using ABI::Windows::Storage::StorageStreamTransaction;
+using ABI::Windows::Storage::FileProperties::BasicProperties;
+using ABI::Windows::Storage::Streams::IOutputStream;
+using ABI::Windows::Storage::Streams::IRandomAccessStream;
+using ABI::Windows::Storage::Streams::IRandomAccessStreamReference;
+using Microsoft::WRL::ComPtr;
+using Microsoft::WRL::Make;
+using Microsoft::WRL::RuntimeClass;
+using Microsoft::WRL::RuntimeClassFlags;
+using Microsoft::WRL::WinRtClassicComMix;
+
+namespace webshare {
+namespace {
+
+class FakeStorageFile final
+    : public RuntimeClass<RuntimeClassFlags<WinRtClassicComMix>,
+                          IStorageFile,
+                          IStorageItem> {
+ public:
+  FakeStorageFile(HSTRING display_name_with_extension,
+                  IStreamedFileDataRequestedHandler* data_requested,
+                  IRandomAccessStreamReference* thumbnail)
+      : streamed_file_data_requested_handler_(data_requested) {
+    // ScopedHString takes ownership of the HSTRING provided to it, but taking
+    // ownership is not an expected behavior when passing an HSTRING to a system
+    // API, so we use a temporary ScopedHString to make a copy we can safely own
+    // and release ownership of the original 'back' to the caller.
+    base::win::ScopedHString holder(display_name_with_extension);
+    display_name_with_extension_ =
+        base::win::ScopedHString::Create(holder.Get());
+    (void)holder.release();
+  }
+  FakeStorageFile(const FakeStorageFile&) = delete;
+  FakeStorageFile& operator=(const FakeStorageFile&) = delete;
+  ~FakeStorageFile() final {
+    EXPECT_FALSE(open_async_in_progress_)
+        << "FakeStorageFile destroyed while open operation is in progress.";
+  }
+
+  // ABI::Windows::Storage::IStorageFile
+  IFACEMETHODIMP get_FileType(HSTRING* value) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+  IFACEMETHODIMP get_ContentType(HSTRING* value) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+  IFACEMETHODIMP OpenAsync(
+      FileAccessMode access_mode,
+      IAsyncOperation<IRandomAccessStream*>** operation) final {
+    if (open_async_in_progress_) {
+      ADD_FAILURE()
+          << "OpenAsync called while an open operation is in progress.";
+      return E_ILLEGAL_METHOD_CALL;
+    }
+
+    auto fake_iasync_operation =
+        Make<base::win::FakeIAsyncOperation<IRandomAccessStream*>>();
+    HRESULT hr = fake_iasync_operation->QueryInterface(IID_PPV_ARGS(operation));
+    if (FAILED(hr)) {
+      EXPECT_HRESULT_SUCCEEDED(hr);
+      return hr;
+    }
+
+    bool success = base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE,
+        base::BindOnce(&FakeStorageFile::OnOpenAsync,
+                       weak_factory_.GetWeakPtr(), fake_iasync_operation));
+    if (!success) {
+      EXPECT_TRUE(success);
+      return E_ASYNC_OPERATION_NOT_STARTED;
+    }
+
+    open_async_in_progress_ = true;
+    return S_OK;
+  }
+  IFACEMETHODIMP OpenTransactedWriteAsync(
+      IAsyncOperation<StorageStreamTransaction*>** operation) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+  IFACEMETHODIMP CopyOverloadDefaultNameAndOptions(
+      IStorageFolder* destination_folder,
+      IAsyncOperation<StorageFile*>** operation) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+  IFACEMETHODIMP CopyOverloadDefaultOptions(
+      IStorageFolder* destination_folder,
+      HSTRING desired_new_name,
+      IAsyncOperation<StorageFile*>** operation) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+  IFACEMETHODIMP CopyOverload(IStorageFolder* destination_folder,
+                              HSTRING desired_new_name,
+                              NameCollisionOption option,
+                              IAsyncOperation<StorageFile*>** operation) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+  IFACEMETHODIMP
+  CopyAndReplaceAsync(IStorageFile* file_to_replace,
+                      IAsyncAction** operation) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+  IFACEMETHODIMP MoveOverloadDefaultNameAndOptions(
+      IStorageFolder* destination_folder,
+      IAsyncAction** operation) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+  IFACEMETHODIMP MoveOverloadDefaultOptions(IStorageFolder* destination_folder,
+                                            HSTRING desired_new_name,
+                                            IAsyncAction** operation) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+  IFACEMETHODIMP
+  MoveOverload(IStorageFolder* destination_folder,
+               HSTRING desired_new_name,
+               NameCollisionOption option,
+               IAsyncAction** operation) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+  IFACEMETHODIMP
+  MoveAndReplaceAsync(IStorageFile* file_to_replace,
+                      IAsyncAction** operation) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+
+  // ABI::Windows::Storage::IStorageItem
+  IFACEMETHODIMP RenameAsyncOverloadDefaultOptions(
+      HSTRING desired_name,
+      IAsyncAction** operation) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+  IFACEMETHODIMP
+  RenameAsync(HSTRING desired_name,
+              NameCollisionOption option,
+              IAsyncAction** operation) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+  IFACEMETHODIMP DeleteAsyncOverloadDefaultOptions(
+      IAsyncAction** operation) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+  IFACEMETHODIMP
+  DeleteAsync(StorageDeleteOption option, IAsyncAction** operation) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+  IFACEMETHODIMP GetBasicPropertiesAsync(
+      IAsyncOperation<BasicProperties*>** operation) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+  IFACEMETHODIMP get_Name(HSTRING* value) final {
+    auto copy =
+        base::win::ScopedHString::Create(display_name_with_extension_.Get());
+    *value = copy.release();
+    return S_OK;
+  }
+  IFACEMETHODIMP get_Path(HSTRING* value) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+  IFACEMETHODIMP
+  get_Attributes(FileAttributes* value) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+  IFACEMETHODIMP
+  get_DateCreated(DateTime* value) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+  IFACEMETHODIMP
+  IsOfType(StorageItemTypes type, boolean* value) final {
+    NOTREACHED();
+    return E_NOTIMPL;
+  }
+
+ private:
+  void OnOpenAsync(ComPtr<base::win::FakeIAsyncOperation<IRandomAccessStream*>>
+                       fake_iasync_operation) {
+    ASSERT_TRUE(open_async_in_progress_);
+    open_async_in_progress_ = false;
+
+    auto fake_stream = Make<FakeRandomAccessStream>();
+
+    ComPtr<IOutputStream> output_stream;
+    ASSERT_HRESULT_SUCCEEDED(fake_stream->GetOutputStreamAt(0, &output_stream));
+    ComPtr<FakeRandomAccessStream> fake_output_stream =
+        static_cast<FakeRandomAccessStream*>(output_stream.Get());
+    ASSERT_TRUE(fake_output_stream);
+
+    fake_output_stream->OnClose(
+        base::BindLambdaForTesting([fake_stream, fake_iasync_operation]() {
+          ComPtr<IRandomAccessStream> random_access_stream;
+          ASSERT_HRESULT_SUCCEEDED(fake_stream.As(&random_access_stream));
+          fake_iasync_operation->CompleteWithResults(random_access_stream);
+        }));
+
+    ASSERT_HRESULT_SUCCEEDED(
+        streamed_file_data_requested_handler_->Invoke(output_stream.Get()));
+  }
+
+  base::win::ScopedHString display_name_with_extension_ =
+      base::win::ScopedHString::Create("");
+  bool open_async_in_progress_ = false;
+  ComPtr<IStreamedFileDataRequestedHandler>
+      streamed_file_data_requested_handler_;
+  base::WeakPtrFactory<FakeStorageFile> weak_factory_{this};
+};
+
+}  // namespace
+
+FakeStorageFileStatics::FakeStorageFileStatics() = default;
+FakeStorageFileStatics::~FakeStorageFileStatics() = default;
+
+IFACEMETHODIMP FakeStorageFileStatics::GetFileFromPathAsync(
+    HSTRING path,
+    IAsyncOperation<StorageFile*>** operation) {
+  NOTREACHED();
+  return E_NOTIMPL;
+}
+
+IFACEMETHODIMP FakeStorageFileStatics::GetFileFromApplicationUriAsync(
+    IUriRuntimeClass* uri,
+    IAsyncOperation<StorageFile*>** operation) {
+  NOTREACHED();
+  return E_NOTIMPL;
+}
+
+IFACEMETHODIMP FakeStorageFileStatics::CreateStreamedFileAsync(
+    HSTRING display_name_with_extension,
+    IStreamedFileDataRequestedHandler* data_requested,
+    IRandomAccessStreamReference* thumbnail,
+    IAsyncOperation<StorageFile*>** operation) {
+  if (!base::win::ScopedHString::ResolveCoreWinRTStringDelayload()) {
+    ADD_FAILURE() << "Attempted to use FakeStorageFileStatics in an "
+                     "environment that doesn't support ScopedHStrings.";
+    return E_UNEXPECTED;
+  }
+
+  auto fake_iasync_operation =
+      Make<base::win::FakeIAsyncOperation<StorageFile*>>();
+  HRESULT hr = fake_iasync_operation->QueryInterface(IID_PPV_ARGS(operation));
+  if (FAILED(hr)) {
+    EXPECT_HRESULT_SUCCEEDED(hr);
+    return hr;
+  }
+
+  auto fake_storage_file = Make<FakeStorageFile>(display_name_with_extension,
+                                                 data_requested, thumbnail);
+  bool success = base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE,
+      base::BindLambdaForTesting([fake_iasync_operation, fake_storage_file]() {
+        fake_iasync_operation->CompleteWithResults(fake_storage_file);
+      }));
+  if (!success) {
+    EXPECT_TRUE(success);
+    return E_ASYNC_OPERATION_NOT_STARTED;
+  }
+
+  return S_OK;
+}
+
+IFACEMETHODIMP FakeStorageFileStatics::ReplaceWithStreamedFileAsync(
+    IStorageFile* file_to_replace,
+    IStreamedFileDataRequestedHandler* data_requested,
+    IRandomAccessStreamReference* thumbnail,
+    IAsyncOperation<StorageFile*>** operation) {
+  NOTREACHED();
+  return E_NOTIMPL;
+}
+
+IFACEMETHODIMP FakeStorageFileStatics::CreateStreamedFileFromUriAsync(
+    HSTRING display_name_with_extension,
+    IUriRuntimeClass* uri,
+    IRandomAccessStreamReference* thumbnail,
+    IAsyncOperation<StorageFile*>** operation) {
+  NOTREACHED();
+  return E_NOTIMPL;
+}
+
+IFACEMETHODIMP FakeStorageFileStatics::ReplaceWithStreamedFileFromUriAsync(
+    IStorageFile* file_to_replace,
+    IUriRuntimeClass* uri,
+    IRandomAccessStreamReference* thumbnail,
+    IAsyncOperation<StorageFile*>** operation) {
+  NOTREACHED();
+  return E_NOTIMPL;
+}
+
+}  // namespace webshare

chrome/browser/webshare/win/fake_storage_file_statics.h

+// Copyright 2020 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_WEBSHARE_WIN_FAKE_STORAGE_FILE_STATICS_H_
+#define CHROME_BROWSER_WEBSHARE_WIN_FAKE_STORAGE_FILE_STATICS_H_
+
+#include <windows.storage.h>
+#include <wrl/implements.h>
+
+namespace webshare {
+
+// Provides an implementation of IStorageFileStatics for use in GTests.
+class __declspec(uuid("70A03B12-27C0-499A-B8AE-18E6060BDEDD"))
+    FakeStorageFileStatics
+    : public Microsoft::WRL::RuntimeClass<
+          Microsoft::WRL::RuntimeClassFlags<Microsoft::WRL::WinRtClassicComMix>,
+          ABI::Windows::Storage::IStorageFileStatics> {
+ public:
+  FakeStorageFileStatics();
+  FakeStorageFileStatics(const FakeStorageFileStatics&) = delete;
+  FakeStorageFileStatics& operator=(const FakeStorageFileStatics&) = delete;
+  ~FakeStorageFileStatics() final;
+
+  // ABI::Windows::Storage::IStorageFileStatics:
+  IFACEMETHODIMP GetFileFromPathAsync(
+      HSTRING path,
+      ABI::Windows::Foundation::IAsyncOperation<
+          ABI::Windows::Storage::StorageFile*>** operation) final;
+  IFACEMETHODIMP GetFileFromApplicationUriAsync(
+      ABI::Windows::Foundation::IUriRuntimeClass* uri,
+      ABI::Windows::Foundation::IAsyncOperation<
+          ABI::Windows::Storage::StorageFile*>** operation) final;
+  IFACEMETHODIMP CreateStreamedFileAsync(
+      HSTRING display_name_with_extension,
+      ABI::Windows::Storage::IStreamedFileDataRequestedHandler* data_requested,
+      ABI::Windows::Storage::Streams::IRandomAccessStreamReference* thumbnail,
+      ABI::Windows::Foundation::IAsyncOperation<
+          ABI::Windows::Storage::StorageFile*>** operation) final;
+  IFACEMETHODIMP ReplaceWithStreamedFileAsync(
+      ABI::Windows::Storage::IStorageFile* file_to_replace,
+      ABI::Windows::Storage::IStreamedFileDataRequestedHandler* data_requested,
+      ABI::Windows::Storage::Streams::IRandomAccessStreamReference* thumbnail,
+      ABI::Windows::Foundation::IAsyncOperation<
+          ABI::Windows::Storage::StorageFile*>** operation) final;
+  IFACEMETHODIMP CreateStreamedFileFromUriAsync(
+      HSTRING display_name_with_extension,
+      ABI::Windows::Foundation::IUriRuntimeClass* uri,
+      ABI::Windows::Storage::Streams::IRandomAccessStreamReference* thumbnail,
+      ABI::Windows::Foundation::IAsyncOperation<
+          ABI::Windows::Storage::StorageFile*>** operation) final;
+  IFACEMETHODIMP ReplaceWithStreamedFileFromUriAsync(
+      ABI::Windows::Storage::IStorageFile* file_to_replace,
+      ABI::Windows::Foundation::IUriRuntimeClass* uri,
+      ABI::Windows::Storage::Streams::IRandomAccessStreamReference* thumbnail,
+      ABI::Windows::Foundation::IAsyncOperation<
+          ABI::Windows::Storage::StorageFile*>** operation) final;
+};
+
+}  // namespace webshare
+
+#endif  // CHROME_BROWSER_WEBSHARE_WIN_FAKE_STORAGE_FILE_STATICS_H_

chrome/browser/webshare/win/fake_storage_file_statics_unittest.cc

+// Copyright 2020 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 "chrome/browser/webshare/win/fake_storage_file_statics.h"
+
+#include <wrl/event.h>
+#include <wrl/implements.h>
+
+#include "base/run_loop.h"
+#include "base/test/task_environment.h"
+#include "base/win/scoped_hstring.h"
+#include "chrome/browser/webshare/win/fake_buffer.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using ABI::Windows::Foundation::IAsyncOperation;
+using ABI::Windows::Foundation::IAsyncOperationCompletedHandler;
+using ABI::Windows::Foundation::IAsyncOperationWithProgress;
+using ABI::Windows::Foundation::IAsyncOperationWithProgressCompletedHandler;
+using ABI::Windows::Foundation::IClosable;
+using ABI::Windows::Storage::FileAccessMode;
+using ABI::Windows::Storage::IStorageFile;
+using ABI::Windows::Storage::IStorageItem;
+using ABI::Windows::Storage::IStreamedFileDataRequestedHandler;
+using ABI::Windows::Storage::StorageFile;
+using ABI::Windows::Storage::Streams::IBuffer;
+using ABI::Windows::Storage::Streams::IInputStream;
+using ABI::Windows::Storage::Streams::InputStreamOptions;
+using ABI::Windows::Storage::Streams::IOutputStream;
+using ABI::Windows::Storage::Streams::IRandomAccessStream;
+using Microsoft::WRL::Callback;
+using Microsoft::WRL::ComPtr;
+using Microsoft::WRL::Make;
+
+namespace webshare {
+
+TEST(FakeStorageFileStaticsTest, CreateStreamedFileAsync) {
+  base::test::SingleThreadTaskEnvironment task_environment;
+  if (!base::win::ScopedHString::ResolveCoreWinRTStringDelayload())
+    return;
+
+  auto file_statics = Make<FakeStorageFileStatics>();
+
+  // Create a streamed file, populated on-demand by the provided callback.
+  ComPtr<IStorageFile> storage_file;
+  {
+    base::RunLoop run_loop;
+    auto file_name = base::win::ScopedHString::Create("MyTestFile.abc");
+    ComPtr<IAsyncOperation<StorageFile*>> create_operation;
+    file_statics->CreateStreamedFileAsync(
+        file_name.get(),
+        Callback<IStreamedFileDataRequestedHandler>([](IOutputStream* stream) {
+          // Create a small buffer of bytes to write to the stream
+          auto buffer = Make<FakeBuffer>(4);
+          EXPECT_HRESULT_SUCCEEDED(buffer->put_Length(4));
+          byte* raw_buffer;
+          EXPECT_HRESULT_SUCCEEDED(buffer->Buffer(&raw_buffer));
+          raw_buffer[0] = 'f';
+          raw_buffer[1] = 'i';
+          raw_buffer[2] = 's';
+          raw_buffer[3] = 'h';
+
+          // Write the bytes to the stream
+          ComPtr<IAsyncOperationWithProgress<UINT32, UINT32>> write_operation;
+          EXPECT_HRESULT_SUCCEEDED(
+              stream->WriteAsync(buffer.Get(), &write_operation));
+          ComPtr<IOutputStream> captured_output_stream = stream;
+          write_operation->put_Completed(
+              Callback<
+                  IAsyncOperationWithProgressCompletedHandler<UINT32, UINT32>>(
+                  [captured_output_stream](
+                      IAsyncOperationWithProgress<UINT32, UINT32>*
+                          async_operation,
+                      AsyncStatus async_status) {
+                    // Verify the write operation completed successfully
+                    EXPECT_EQ(async_status, AsyncStatus::Completed);
+                    UINT32 result;
+                    EXPECT_HRESULT_SUCCEEDED(
+                        async_operation->GetResults(&result));
+                    EXPECT_EQ(result, 4u);
+
+                    // Flush the stream
+                    ComPtr<IAsyncOperation<bool>> flush_operation;
+                    EXPECT_HRESULT_SUCCEEDED(
+                        captured_output_stream->FlushAsync(&flush_operation));
+                    flush_operation->put_Completed(
+                        Callback<IAsyncOperationCompletedHandler<bool>>(
+                            [captured_output_stream](
+                                IAsyncOperation<bool>* async_operation,
+                                AsyncStatus async_status) {
+                              // Verify the flush operation completed
+                              // successfully
+                              EXPECT_EQ(async_status, AsyncStatus::Completed);
+                              boolean result;
+                              EXPECT_HRESULT_SUCCEEDED(
+                                  async_operation->GetResults(&result));
+                              EXPECT_EQ(result, TRUE);
+
+                              // Close the stream
+                              ComPtr<IClosable> closable;
+                              EXPECT_HRESULT_SUCCEEDED(
+                                  captured_output_stream.As(&closable));
+                              EXPECT_HRESULT_SUCCEEDED(closable->Close());
+                              return S_OK;
+                            })
+                            .Get());
+                    return S_OK;
+                  })
+                  .Get());
+          return S_OK;
+        }).Get(),
+        /*thumbnail*/ nullptr, &create_operation);
+    ASSERT_HRESULT_SUCCEEDED(create_operation->put_Completed(
+        Callback<IAsyncOperationCompletedHandler<StorageFile*>>(
+            [&run_loop, &storage_file](
+                IAsyncOperation<StorageFile*>* async_operation,
+                AsyncStatus async_status) {
+              EXPECT_EQ(async_status, AsyncStatus::Completed);
+              EXPECT_HRESULT_SUCCEEDED(
+                  async_operation->GetResults(&storage_file));
+              run_loop.Quit();
+              return S_OK;
+            })
+            .Get()));
+    run_loop.Run();
+  }
+
+  // Verify the created streamed file has the expected name
+  ComPtr<IStorageItem> storage_item;
+  ASSERT_HRESULT_SUCCEEDED(storage_file.As(&storage_item));
+  HSTRING name;
+  ASSERT_HRESULT_SUCCEEDED(storage_item->get_Name(&name));
+  ASSERT_EQ(base::win::ScopedHString(name).GetAsUTF8(), "MyTestFile.abc");
+
+  // Open the streamed file
+  ComPtr<IRandomAccessStream> opened_stream;
+  {
+    base::RunLoop run_loop;
+    ComPtr<IAsyncOperation<IRandomAccessStream*>> open_operation;
+    ASSERT_HRESULT_SUCCEEDED(storage_file->OpenAsync(
+        FileAccessMode::FileAccessMode_Read, &open_operation));
+    ASSERT_HRESULT_SUCCEEDED(open_operation->put_Completed(
+        Callback<IAsyncOperationCompletedHandler<IRandomAccessStream*>>(
+            [&run_loop, &opened_stream](
+                IAsyncOperation<IRandomAccessStream*>* async_operation,
+                AsyncStatus async_status) {
+              EXPECT_EQ(async_status, AsyncStatus::Completed);
+              EXPECT_HRESULT_SUCCEEDED(
+                  async_operation->GetResults(&opened_stream));
+              run_loop.Quit();
+              return S_OK;
+            })
+            .Get()));
+    run_loop.Run();
+  }
+
+  ComPtr<IInputStream> input_stream;
+  ASSERT_HRESULT_SUCCEEDED(opened_stream->GetInputStreamAt(0, &input_stream));
+  UINT64 size;
+  ASSERT_HRESULT_SUCCEEDED(opened_stream->get_Size(&size));
+
+  // Read the opened stream
+  auto buffer = Make<FakeBuffer>(size);
+  {
+    base::RunLoop run_loop;
+    ComPtr<IAsyncOperationWithProgress<IBuffer*, UINT32>> read_operation;
+    ASSERT_HRESULT_SUCCEEDED(input_stream->ReadAsync(
+        buffer.Get(), size, InputStreamOptions::InputStreamOptions_None,
+        &read_operation));
+    ASSERT_HRESULT_SUCCEEDED(read_operation->put_Completed(
+        Callback<IAsyncOperationWithProgressCompletedHandler<IBuffer*, UINT32>>(
+            [&run_loop, &buffer](
+                IAsyncOperationWithProgress<IBuffer*, UINT32>* async_operation,
+                AsyncStatus async_status) {
+              EXPECT_EQ(async_status, AsyncStatus::Completed);
+              ComPtr<IBuffer> result;
+              EXPECT_HRESULT_SUCCEEDED(async_operation->GetResults(&result));
+              EXPECT_EQ(result.Get(), buffer.Get());
+              run_loop.Quit();
+              return S_OK;
+            })
+            .Get()));
+    run_loop.Run();
+  }
+
+  // Verify the stream read from the file has content matching what our
+  // DataRequested callback provided
+  UINT32 length;
+  ASSERT_HRESULT_SUCCEEDED(buffer->get_Length(&length));
+  ASSERT_EQ(length, size);
+  byte* raw_buffer;
+  ASSERT_HRESULT_SUCCEEDED(buffer->Buffer(&raw_buffer));
+  ASSERT_EQ(raw_buffer[0], 'f');
+  ASSERT_EQ(raw_buffer[1], 'i');
+  ASSERT_EQ(raw_buffer[2], 's');
+  ASSERT_EQ(raw_buffer[3], 'h');
+}
+
+}  // namespace webshare

chrome/test/BUILD.gn

@@ -330,6 +330,8 @@ static_library("test_support") {
       "../browser/webshare/win/fake_iasync_operation_with_progress.h",
       "../browser/webshare/win/fake_random_access_stream.cc",
       "../browser/webshare/win/fake_random_access_stream.h",
+      "../browser/webshare/win/fake_storage_file_statics.cc",
+      "../browser/webshare/win/fake_storage_file_statics.h",
       "../browser/webshare/win/scoped_fake_data_transfer_manager_interop.cc",
       "../browser/webshare/win/scoped_fake_data_transfer_manager_interop.h",
       "//chrome/app/chrome_crash_reporter_client_win.cc",
@@ -5819,6 +5821,7 @@ test("unit_tests") {
       "../browser/webshare/win/fake_data_transfer_manager_interop_unittest.cc",
       "../browser/webshare/win/fake_data_transfer_manager_unittest.cc",
       "../browser/webshare/win/fake_random_access_stream_unittest.cc",
+      "../browser/webshare/win/fake_storage_file_statics_unittest.cc",
       "../browser/webshare/win/show_share_ui_for_window_operation_unittest.cc",
     ]
     deps += [