chrome: Add support for Alloy style browsers and windows (see #3681)

Split the Alloy runtime into bootstrap and style components. Support
creation of Alloy style browsers and windows with the Chrome runtime.
Chrome runtime (`--enable-chrome-runtime`) + Alloy style
(`--use-alloy-style`) supports Views (`--use-views`), native parent
(`--use-native`) and windowless rendering
(`--off-screen-rendering-enabled`).

Print preview is supported in all cases except with windowless rendering
on all platforms and native parent on MacOS. It is disabled by default
with Alloy style for legacy compatibility. Where supported it can be
enabled or disabled globally using `--[enable|disable]-print-preview` or
configured on a per-RequestContext basis using the
`printing.print_preview_disabled` preference. It also behaves as
expected when triggered via the PDF viewer print button.

Chrome runtime + Alloy style behavior differs from Alloy runtime in the
following significant ways:

- Supports Chrome error pages by default.
- DevTools popups are Chrome style only (cannot be windowless).
- The Alloy extension API will not supported.

Chrome runtime + Alloy style passes all expected Alloy ceftests except
the following:

- `DisplayTest.AutoResize` (Alloy extension API not supported)
- `DownloadTest.*` (Download API not yet supported)
- `ExtensionTest.*` (Alloy extension API not supported)

This change also adds Chrome runtime support for
CefContextMenuHandler::RunContextMenu (see #3293).

This change also explicitly blocks (and doesn't retry) FrameAttached
requests from PDF viewer and print preview excluded frames (see #3664).

Known issues specific to Chrome runtime + Alloy style:
- DevTools popup with windowless rendering doesn't load successfully.
  Use windowed rendering or remote debugging as a workaround.
- Chrome style Window with Alloy style BrowserView (`--use-alloy-style
  --use-chrome-style-window`) does not show Chrome theme changes.

To test:
- Run `ceftests --enable-chrome-runtime --use-alloy-style
       [--use-chrome-style-window] [--use-views|--use-native]
       --gtest_filter=...`
- Run `cefclient --enable-chrome-runtime --use-alloy-style
       [--use-chrome-style-window]
       [--use-views|--use-native|--off-screen-rendering-enabled]`
- Run `cefsimple --enable-chrome-runtime --use-alloy-style [--use-views]`

libcef/browser/alloy/devtools/devtools_file_manager.cc

@@ -0,0 +1,207 @@
+// Copyright 2019 The Chromium Embedded Framework Authors. Portions 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.
+
+#include "libcef/browser/alloy/devtools/devtools_file_manager.h"
+
+#include "libcef/browser/alloy/alloy_browser_host_impl.h"
+
+#include "base/files/file_path.h"
+#include "base/files/file_util.h"
+#include "base/functional/bind.h"
+#include "base/functional/callback.h"
+#include "base/hash/md5.h"
+#include "base/json/json_writer.h"
+#include "base/json/values_util.h"
+#include "base/lazy_instance.h"
+#include "base/path_service.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/task/sequenced_task_runner.h"
+#include "base/task/thread_pool.h"
+#include "base/values.h"
+#include "chrome/common/pref_names.h"
+#include "components/prefs/scoped_user_pref_update.h"
+#include "content/public/browser/web_contents.h"
+
+namespace {
+
+base::LazyInstance<base::FilePath>::Leaky g_last_save_path =
+    LAZY_INSTANCE_INITIALIZER;
+
+void WriteToFile(const base::FilePath& path, const std::string& content) {
+  DCHECK(!path.empty());
+  base::WriteFile(path, content.c_str(), content.length());
+}
+
+void AppendToFile(const base::FilePath& path, const std::string& content) {
+  DCHECK(!path.empty());
+  base::AppendToFile(path, base::StringPiece(content));
+}
+
+}  // namespace
+
+CefDevToolsFileManager::CefDevToolsFileManager(
+    AlloyBrowserHostImpl* browser_impl,
+    PrefService* prefs)
+    : browser_impl_(browser_impl),
+      prefs_(prefs),
+      file_task_runner_(
+          base::ThreadPool::CreateSequencedTaskRunner({base::MayBlock()})),
+      weak_factory_(this) {}
+
+void CefDevToolsFileManager::SaveToFile(const std::string& url,
+                                        const std::string& content,
+                                        bool save_as) {
+  Save(url, content, save_as,
+       base::BindOnce(&CefDevToolsFileManager::FileSavedAs,
+                      weak_factory_.GetWeakPtr(), url),
+       base::BindOnce(&CefDevToolsFileManager::CanceledFileSaveAs,
+                      weak_factory_.GetWeakPtr(), url));
+}
+
+void CefDevToolsFileManager::AppendToFile(const std::string& url,
+                                          const std::string& content) {
+  Append(url, content,
+         base::BindOnce(&CefDevToolsFileManager::AppendedTo,
+                        weak_factory_.GetWeakPtr(), url));
+}
+
+void CefDevToolsFileManager::Save(const std::string& url,
+                                  const std::string& content,
+                                  bool save_as,
+                                  SaveCallback saveCallback,
+                                  CancelCallback cancelCallback) {
+  auto it = saved_files_.find(url);
+  if (it != saved_files_.end() && !save_as) {
+    SaveAsFileSelected(url, content, std::move(saveCallback), it->second);
+    return;
+  }
+
+  const base::Value::Dict& file_map =
+      prefs_->GetDict(prefs::kDevToolsEditedFiles);
+  base::FilePath initial_path;
+
+  if (const base::Value* path_value = file_map.Find(base::MD5String(url))) {
+    std::optional<base::FilePath> path = base::ValueToFilePath(*path_value);
+    if (path) {
+      initial_path = std::move(*path);
+    }
+  }
+
+  if (initial_path.empty()) {
+    GURL gurl(url);
+    std::string suggested_file_name =
+        gurl.is_valid() ? gurl.ExtractFileName() : url;
+
+    if (suggested_file_name.length() > 64) {
+      suggested_file_name = suggested_file_name.substr(0, 64);
+    }
+
+    if (!g_last_save_path.Pointer()->empty()) {
+      initial_path = g_last_save_path.Pointer()->DirName().AppendASCII(
+          suggested_file_name);
+    } else {
+      // Use the temp directory. It may be an empty value.
+      base::PathService::Get(base::DIR_TEMP, &initial_path);
+      initial_path = initial_path.AppendASCII(suggested_file_name);
+    }
+  }
+
+  blink::mojom::FileChooserParams params;
+  params.mode = blink::mojom::FileChooserParams::Mode::kSave;
+  if (!initial_path.empty()) {
+    params.default_file_name = initial_path;
+    if (!initial_path.Extension().empty()) {
+      params.accept_types.push_back(CefString(initial_path.Extension()));
+    }
+  }
+
+  browser_impl_->RunFileChooserForBrowser(
+      params,
+      base::BindOnce(&CefDevToolsFileManager::SaveAsDialogDismissed,
+                     weak_factory_.GetWeakPtr(), url, content,
+                     std::move(saveCallback), std::move(cancelCallback)));
+}
+
+void CefDevToolsFileManager::SaveAsDialogDismissed(
+    const std::string& url,
+    const std::string& content,
+    SaveCallback saveCallback,
+    CancelCallback cancelCallback,
+    const std::vector<base::FilePath>& file_paths) {
+  if (file_paths.size() == 1) {
+    SaveAsFileSelected(url, content, std::move(saveCallback), file_paths[0]);
+  } else {
+    std::move(cancelCallback).Run();
+  }
+}
+
+void CefDevToolsFileManager::SaveAsFileSelected(const std::string& url,
+                                                const std::string& content,
+                                                SaveCallback callback,
+                                                const base::FilePath& path) {
+  *g_last_save_path.Pointer() = path;
+  saved_files_[url] = path;
+
+  ScopedDictPrefUpdate update(prefs_, prefs::kDevToolsEditedFiles);
+  update->Set(base::MD5String(url), base::FilePathToValue(path));
+  std::string file_system_path = path.AsUTF8Unsafe();
+  std::move(callback).Run(file_system_path);
+  file_task_runner_->PostTask(FROM_HERE,
+                              base::BindOnce(&::WriteToFile, path, content));
+}
+
+void CefDevToolsFileManager::FileSavedAs(const std::string& url,
+                                         const std::string& file_system_path) {
+  base::Value url_value(url);
+  base::Value file_system_path_value(file_system_path);
+  CallClientFunction("DevToolsAPI.savedURL", &url_value,
+                     &file_system_path_value, nullptr);
+}
+
+void CefDevToolsFileManager::CanceledFileSaveAs(const std::string& url) {
+  base::Value url_value(url);
+  CallClientFunction("DevToolsAPI.canceledSaveURL", &url_value, nullptr,
+                     nullptr);
+}
+
+void CefDevToolsFileManager::Append(const std::string& url,
+                                    const std::string& content,
+                                    AppendCallback callback) {
+  auto it = saved_files_.find(url);
+  if (it == saved_files_.end()) {
+    return;
+  }
+  std::move(callback).Run();
+  file_task_runner_->PostTask(
+      FROM_HERE, base::BindOnce(&::AppendToFile, it->second, content));
+}
+
+void CefDevToolsFileManager::AppendedTo(const std::string& url) {
+  base::Value url_value(url);
+  CallClientFunction("DevToolsAPI.appendedToURL", &url_value, nullptr, nullptr);
+}
+
+void CefDevToolsFileManager::CallClientFunction(
+    const std::string& function_name,
+    const base::Value* arg1,
+    const base::Value* arg2,
+    const base::Value* arg3) {
+  std::string javascript = function_name + "(";
+  if (arg1) {
+    std::string json;
+    base::JSONWriter::Write(*arg1, &json);
+    javascript.append(json);
+    if (arg2) {
+      base::JSONWriter::Write(*arg2, &json);
+      javascript.append(", ").append(json);
+      if (arg3) {
+        base::JSONWriter::Write(*arg3, &json);
+        javascript.append(", ").append(json);
+      }
+    }
+  }
+  javascript.append(");");
+  browser_impl_->web_contents()->GetPrimaryMainFrame()->ExecuteJavaScript(
+      base::UTF8ToUTF16(javascript), base::NullCallback());
+}