gfx: Make all GpuMemoryBufferTypes platform scoped

Some GpuMemoryBufferPlatformHandle union members are used only on one
platform but are defined for all platforms. This CL restricts
platform-specific members to desired platform.

Bug: 863011
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: I6c09e49db157d9d91dc5caeac939ca334f9054ba
Reviewed-on: https://chromium-review.googlesource.com/c/1290917Reviewed-by: Antoine Labour <piman@chromium.org>
Reviewed-by: Daniele Castagna <dcastagna@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Alexandr Ilin <alexilin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604049}

ui/gfx/mojo/BUILD.gn

@@ -23,6 +23,10 @@ mojom("mojo") {
     "//mojo/public/mojom/base",
     "//ui/gfx/geometry/mojo",
   ]
+
+  if (is_linux || is_chromeos) {
+    enabled_features = [ "supports_native_pixmap" ]
+  }
 }
 
 mojom("test_interfaces") {

ui/gfx/mojo/buffer_types.mojom

@@ -46,22 +46,13 @@ struct BufferUsageAndFormat {
   BufferFormat format;
 };
 
-// gfx::GpuMemoryBufferType
-enum GpuMemoryBufferType {
-  EMPTY_BUFFER,
-  SHARED_MEMORY_BUFFER,
-  IO_SURFACE_BUFFER,
-  NATIVE_PIXMAP,
-  DXGI_SHARED_HANDLE,
-  ANDROID_HARDWARE_BUFFER,
-};
-
 // gfx::GpuMemoryBufferId
 struct GpuMemoryBufferId {
   int32 id;
 };
 
 // gfx::NativePixmapPlane
+[EnableIf=supports_native_pixmap]
 struct NativePixmapPlane {
   uint32 stride;
   int32 offset;
@@ -70,6 +61,7 @@ struct NativePixmapPlane {
 };
 
 // gfx::NativePixmapHandle
+[EnableIf=supports_native_pixmap]
 struct NativePixmapHandle {
   // A file descriptor for the underlying memory object (usually dmabuf).
   array<handle> fds;
@@ -92,10 +84,12 @@ struct AHardwareBufferHandle {
 };
 
 union GpuMemoryBufferPlatformHandle {
-  // TODO(676224): Use preprocessor to restrict platform-specific members to
-  // desired platform.
   mojo_base.mojom.UnsafeSharedMemoryRegion shared_memory_handle;
+
+  [EnableIf=supports_native_pixmap]
   NativePixmapHandle native_pixmap_handle;
+
+  [EnableIf=is_mac]
   handle mach_port;
 
   [EnableIf=is_win]

ui/gfx/mojo/buffer_types_struct_traits.cc

@@ -28,14 +28,13 @@ bool StructTraits<gfx::mojom::BufferUsageAndFormatDataView,
   return data.ReadUsage(&out->usage) && data.ReadFormat(&out->format);
 }
 
+#if defined(OS_LINUX)
 std::vector<mojo::ScopedHandle>
 StructTraits<gfx::mojom::NativePixmapHandleDataView, gfx::NativePixmapHandle>::
     fds(const gfx::NativePixmapHandle& pixmap_handle) {
   std::vector<mojo::ScopedHandle> handles;
-#if defined(OS_LINUX)
   for (const base::FileDescriptor& fd : pixmap_handle.fds)
     handles.emplace_back(mojo::WrapPlatformFile(fd.fd));
-#endif  // defined(OS_LINUX)
   return handles;
 }
 
@@ -43,7 +42,6 @@ bool StructTraits<
     gfx::mojom::NativePixmapHandleDataView,
     gfx::NativePixmapHandle>::Read(gfx::mojom::NativePixmapHandleDataView data,
                                    gfx::NativePixmapHandle* out) {
-#if defined(OS_LINUX)
   mojo::ArrayDataView<mojo::ScopedHandle> handles_data_view;
   data.GetFdsDataView(&handles_data_view);
   for (size_t i = 0; i < handles_data_view.size(); ++i) {
@@ -56,10 +54,8 @@ bool StructTraits<
     out->fds.push_back(base::FileDescriptor(platform_file, auto_close));
   }
   return data.ReadPlanes(&out->planes);
-#else
-  return false;
-#endif
 }
+#endif  // defined(OS_LINUX)
 
 gfx::mojom::GpuMemoryBufferPlatformHandlePtr StructTraits<
     gfx::mojom::GpuMemoryBufferHandleDataView,
@@ -71,16 +67,13 @@ gfx::mojom::GpuMemoryBufferPlatformHandlePtr StructTraits<
     case gfx::SHARED_MEMORY_BUFFER:
       return gfx::mojom::GpuMemoryBufferPlatformHandle::NewSharedMemoryHandle(
           std::move(handle.region));
-    case gfx::NATIVE_PIXMAP: {
+    case gfx::NATIVE_PIXMAP:
 #if defined(OS_LINUX)
       return gfx::mojom::GpuMemoryBufferPlatformHandle::NewNativePixmapHandle(
           handle.native_pixmap_handle);
 #else
-      static base::NoDestructor<gfx::NativePixmapHandle> pixmap_handle;
-      return gfx::mojom::GpuMemoryBufferPlatformHandle::NewNativePixmapHandle(
-          *pixmap_handle);
+      break;
 #endif
-    }
     case gfx::IO_SURFACE_BUFFER:
 #if defined(OS_MACOSX) && !defined(OS_IOS)
       return gfx::mojom::GpuMemoryBufferPlatformHandle::NewMachPort(
@@ -151,17 +144,14 @@ bool StructTraits<gfx::mojom::GpuMemoryBufferHandleDataView,
       out->type = gfx::SHARED_MEMORY_BUFFER;
       out->region = std::move(platform_handle->get_shared_memory_handle());
       return true;
+#if defined(OS_LINUX)
     case gfx::mojom::GpuMemoryBufferPlatformHandleDataView::Tag::
         NATIVE_PIXMAP_HANDLE:
-#if defined(OS_LINUX)
       out->type = gfx::NATIVE_PIXMAP;
       out->native_pixmap_handle = platform_handle->get_native_pixmap_handle();
       return true;
-#else
-      return false;
-#endif
+#elif defined(OS_MACOSX) && !defined(OS_IOS)
     case gfx::mojom::GpuMemoryBufferPlatformHandleDataView::Tag::MACH_PORT: {
-#if defined(OS_MACOSX) && !defined(OS_IOS)
       out->type = gfx::IO_SURFACE_BUFFER;
       mach_port_t mach_port;
       MojoResult unwrap_result = mojo::UnwrapMachPort(
@@ -170,11 +160,8 @@ bool StructTraits<gfx::mojom::GpuMemoryBufferHandleDataView,
         return false;
       out->mach_port.reset(mach_port);
       return true;
-#else
-      return false;
-#endif
     }
-#if defined(OS_WIN)
+#elif defined(OS_WIN)
     case gfx::mojom::GpuMemoryBufferPlatformHandleDataView::Tag::DXGI_HANDLE: {
       out->type = gfx::DXGI_SHARED_HANDLE;
       HANDLE handle;
@@ -185,8 +172,7 @@ bool StructTraits<gfx::mojom::GpuMemoryBufferHandleDataView,
       out->dxgi_handle = IPC::PlatformFileForTransit(handle);
       return true;
     }
-#endif
-#if defined(OS_ANDROID)
+#elif defined(OS_ANDROID)
     case gfx::mojom::GpuMemoryBufferPlatformHandleDataView::Tag::
         ANDROID_HARDWARE_BUFFER_HANDLE: {
       out->type = gfx::ANDROID_HARDWARE_BUFFER;

ui/gfx/mojo/buffer_types_struct_traits.h

@@ -189,6 +189,7 @@ struct StructTraits<gfx::mojom::GpuMemoryBufferIdDataView,
   }
 };
 
+#if defined(OS_LINUX)
 template <>
 struct StructTraits<gfx::mojom::NativePixmapPlaneDataView,
                     gfx::NativePixmapPlane> {
@@ -217,14 +218,6 @@ struct StructTraits<gfx::mojom::NativePixmapPlaneDataView,
 template <>
 struct StructTraits<gfx::mojom::NativePixmapHandleDataView,
                     gfx::NativePixmapHandle> {
-  static bool IsNull(const gfx::NativePixmapHandle& handle) {
-#if defined(OS_LINUX)
-    return false;
-#else
-    // NativePixmapHandle are not used on non-linux platforms.
-    return true;
-#endif
-  }
   static std::vector<mojo::ScopedHandle> fds(
       const gfx::NativePixmapHandle& pixmap_handle);
 
@@ -236,6 +229,7 @@ struct StructTraits<gfx::mojom::NativePixmapHandleDataView,
   static bool Read(gfx::mojom::NativePixmapHandleDataView data,
                    gfx::NativePixmapHandle* out);
 };
+#endif  // defined(OS_LINUX)
 
 template <>
 struct StructTraits<gfx::mojom::GpuMemoryBufferHandleDataView,