[Fuchsia] Enable Vulkan in WebEngine and WebRunner

Now Vulkan and out-of-process rasterization is supported in WebEngine.
It's enabled only when it detects that the Vulkan loader service is
present in the service directory passed during Context creation. Also
removed Vulkan loader service from the CastRunner manifest, so for
now WebRunner is the only client that will have Vulkan enabled.

Bug: 962617
Change-Id: I5994b825057aebfc10ff5a828c7ace947aec3816
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1618242
Commit-Queue: Sergey Ulanov <sergeyu@chromium.org>
Reviewed-by: Wez <wez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#669026}

fuchsia/engine/context_provider_impl.cc

@@ -6,9 +6,14 @@
 
 #include <fuchsia/sys/cpp/fidl.h>
 #include <lib/async/default.h>
+#include <lib/fdio/directory.h>
+#include <lib/fdio/fd.h>
 #include <lib/fdio/io.h>
 #include <lib/zx/job.h>
 #include <stdio.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
 #include <zircon/processargs.h>
 
 #include <utility>
@@ -17,6 +22,7 @@
 #include "base/base_paths_fuchsia.h"
 #include "base/bind.h"
 #include "base/command_line.h"
+#include "base/files/scoped_file.h"
 #include "base/fuchsia/default_job.h"
 #include "base/fuchsia/fuchsia_logging.h"
 #include "base/logging.h"
@@ -47,6 +53,31 @@ zx::channel ValidateDirectoryAndTakeChannel(
   return zx::channel();
 }
 
+// Verifies that Vulkan loader service is provided by the specified service
+// directory.
+bool CheckVulkanSupport(
+    const fidl::InterfaceHandle<::fuchsia::io::Directory>& directory_handle,
+    bool* enable_vulkan) {
+  zx::channel dir_channel(fdio_service_clone(directory_handle.channel().get()));
+  if (!dir_channel)
+    return false;
+
+  base::ScopedFD dir_fd;
+  zx_status_t status = fdio_fd_create(dir_channel.release(),
+                                      base::ScopedFD::Receiver(dir_fd).get());
+  if (status != ZX_OK) {
+    ZX_DLOG(ERROR, status) << "fdio_fd_create()";
+    return false;
+  }
+
+  struct stat statbuf;
+  int result =
+      fstatat(dir_fd.get(), "fuchsia.vulkan.loader.Loader", &statbuf, 0);
+  *enable_vulkan = result == 0;
+
+  return true;
+}
+
 }  // namespace
 
 ContextProviderImpl::ContextProviderImpl() = default;
@@ -67,11 +98,22 @@ void ContextProviderImpl::Create(
     return;
   }
 
+  fidl::InterfaceHandle<::fuchsia::io::Directory> service_directory =
+      std::move(*params.mutable_service_directory());
+
+  // Enable Vulkan if the Vulkan loader service is present in the service
+  // directory.
+  bool enable_vulkan = false;
+  if (!CheckVulkanSupport(service_directory, &enable_vulkan)) {
+    // TODO(crbug.com/934539): Add type epitaph.
+    DLOG(WARNING) << "Invalid |service_directory| in CreateContextParams.";
+    return;
+  }
+
   base::LaunchOptions launch_options;
   service_manager::SandboxPolicyFuchsia sandbox_policy;
   sandbox_policy.Initialize(service_manager::SANDBOX_TYPE_WEB_CONTEXT);
-  sandbox_policy.SetServiceDirectory(
-      std::move(*params.mutable_service_directory()));
+  sandbox_policy.SetServiceDirectory(std::move(service_directory));
   sandbox_policy.UpdateLaunchOptionsForSandbox(&launch_options);
 
   // Transfer the ContextRequest handle to a well-known location in the child
@@ -109,8 +151,9 @@ void ContextProviderImpl::Create(
   }
   launch_options.job_handle = job.get();
 
+  base::CommandLine launch_command = *base::CommandLine::ForCurrentProcess();
+
   // Connect DevTools listeners to the new Context process.
-  base::CommandLine launch_command(*base::CommandLine::ForCurrentProcess());
   std::vector<zx::channel> devtools_listener_channels;
   if (devtools_listeners_.size() != 0) {
     std::vector<std::string> handles_ids;
@@ -129,6 +172,17 @@ void ContextProviderImpl::Create(
                                       base::JoinString(handles_ids, ","));
   }
 
+  // Enable Vulkan when the Vulkan loader service is included in the service
+  // directory.
+  // TODO(https://crbug.com/962617): Enable Vulkan by default and remove this
+  // hack.
+  if (enable_vulkan) {
+    launch_command.AppendSwitchASCII(
+        "--enable-features", "DefaultEnableOopRasterization,UseSkiaRenderer");
+    launch_command.AppendSwitch("--use-vulkan");
+    launch_command.AppendSwitchASCII("--use-gl", "stub");
+  }
+
   if (launch_for_test_)
     launch_for_test_.Run(launch_command, launch_options);
   else

fuchsia/runners/cast/sandbox_policy

@@ -14,7 +14,6 @@
       "fuchsia.ui.input.ImeService",
       "fuchsia.ui.input.ImeVisibilityService",
       "fuchsia.ui.scenic.Scenic",
-      "fuchsia.vulkan.loader.Loader",
       "fuchsia.web.ContextProvider"
   ]
 }