macOS: Add support for and enable the V2 sandbox (issue #2459)

The CEF_USE_SANDBOX define is now used on all platforms.

include/cef_sandbox_mac.h

@@ -0,0 +1,87 @@
+// Copyright (c) 2018 Marshall A. Greenblatt. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the name Chromium Embedded
+// Framework nor the names of its contributors may be used to endorse
+// or promote products derived from this software without specific prior
+// written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef CEF_INCLUDE_CEF_SANDBOX_MAC_H_
+#define CEF_INCLUDE_CEF_SANDBOX_MAC_H_
+#pragma once
+
+#include "include/base/cef_build.h"
+
+#if defined(OS_MACOSX)
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// The sandbox is used to restrict sub-processes (renderer, plugin, GPU, etc)
+// from directly accessing system resources. This helps to protect the user
+// from untrusted and potentially malicious Web content.
+// See http://www.chromium.org/developers/design-documents/sandbox for
+// complete details.
+//
+// To enable the sandbox on macOS the following requirements must be met:
+// 1. Link the helper process executable with the cef_sandbox static library.
+// 2. Call the cef_sandbox_initialize() function at the beginning of the
+//    helper executable main() function and before loading the CEF framework
+//    library. See include/wrapper/cef_library_loader.h for example usage.
+
+///
+// Initialize the sandbox for this process. Returns the sandbox context
+// handle on success or NULL on failure. The returned handle should be
+// passed to cef_sandbox_destroy() immediately before process termination.
+///
+void* cef_sandbox_initialize(int argc, char** argv);
+
+///
+// Destroy the specified sandbox context handle.
+///
+void cef_sandbox_destroy(void* sandbox_context);
+
+#ifdef __cplusplus
+}
+
+///
+// Scoped helper for managing the life span of a sandbox context handle.
+///
+class CefScopedSandboxContext {
+ public:
+  CefScopedSandboxContext();
+  ~CefScopedSandboxContext();
+
+  // Load the sandbox for this process. Returns true on success.
+  bool Initialize(int argc, char** argv);
+
+ private:
+  void* sandbox_context_;
+};
+#endif  // __cplusplus
+
+#endif  // defined(OS_MACOSX)
+
+#endif  // CEF_INCLUDE_CEF_SANDBOX_MAC_H_

include/wrapper/cef_library_loader.h

@@ -66,22 +66,34 @@ int cef_unload_library();
 //
 // Example usage in the main process:
 //
+//   #include "include/wrapper/cef_library_loader.h"
+//
 //   int main(int argc, char* argv[]) {
+//     // Dynamically load the CEF framework library.
 //     CefScopedLibraryLoader library_loader;
 //     if (!library_loader.LoadInMain())
 //       return 1;
 //
-//     // Rest of the function here...
+//     // Continue with CEF initialization...
 //   }
 //
 // Example usage in the helper process:
 //
+//   #include "include/cef_sandbox_mac.h"
+//   #include "include/wrapper/cef_library_loader.h"
+//
 //   int main(int argc, char* argv[]) {
+//     // Initialize the macOS sandbox for this helper process.
+//     CefScopedSandboxContext sandbox_context;
+//     if (!sandbox_context.Initialize(argc, argv))
+//       return 1;
+//
+//     // Dynamically load the CEF framework library.
 //     CefScopedLibraryLoader library_loader;
 //     if (!library_loader.LoadInHelper())
 //       return 1;
 //
-//     // Rest of the function here...
+//     // Continue with CEF initialization...
 //   }
 ///
 class CefScopedLibraryLoader {