Added initial Vulkan build files as well as a basic implementation file.

gpu/vulkan/BUILD.gn

+# Copyright 2016 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.
+
+import("//build/config/ui.gni")
+
+config("vulkan_config") {
+  defines = [ "ENABLE_VULKAN" ]
+  if (use_x11) {
+    defines += [ "VK_USE_PLATFORM_XLIB_KHR" ]
+  }
+}
+
+component("vulkan") {
+  output_name = "vulkan_wrapper"
+
+  if (is_linux && enable_vulkan) {
+    assert(use_x11, "Vulkan only support x11 at this point.")
+    sources = [
+      "vulkan_export.h",
+      "vulkan_implementation.cc",
+      "vulkan_implementation.h",
+      "vulkan_surface.cc",
+      "vulkan_surface.h",
+    ]
+
+    configs += [ "//build/config:precompiled_headers" ]

[Nico, 2016/03/09 02:43:33]

(nit: atm this target is so small that using this is discouraged, as building
the pch is likely slower than building all the cc files)

+    defines = [ "VULKAN_IMPLEMENTATION" ]
+
+    all_dependent_configs = [ ":vulkan_config" ]
+    libs = [ "vulkan" ]
+
+    include_dirs = [ "/usr/include" ]
+    if (target_cpu == "x64") {
+      lib_dirs = [ "/usr/lib/x86_64-linux-gnu" ]
+    } else {
+      assert(false, "Unsupported vulkan target: " + target_cpu)
+    }
+
+    deps = [
+      "//base",
+      "//ui/base",
+      "//ui/gfx",
+    ]
+
+    if (use_x11) {
+      deps += [ "//ui/gfx/x" ]
+      configs += [ "//build/config/linux:x11" ]
+    }
+  }
+}