Move vulkan headers from third_party to include/third_party.

Bug: skia:
Change-Id: I7174c6da075c0fd3d6238a5556439f42d6b97659
Reviewed-on: https://skia-review.googlesource.com/c/176680
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index 5b6f7e2..201b86c 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -189,7 +189,7 @@
   if (skia_enable_gpu) {
     include_dirs += [ "src/gpu" ]
     if (is_skia_dev_build && skia_use_vulkan) {
-      include_dirs += [ "third_party/vulkan" ]
+      include_dirs += [ "include/third_party/vulkan" ]
       include_dirs += [ "tools/gpu/vk" ]
     }
   }
@@ -1174,7 +1174,7 @@
 
     # We add this directory to simulate the client already have
     # vulkan/vulkan_core.h on their path.
-    include_dirs = [ "third_party/vulkan" ]
+    include_dirs = [ "include/third_party/vulkan" ]
   }
 
   template("test_lib") {
@@ -1432,7 +1432,7 @@
       deps += [ "//third_party/angle2" ]
       sources += [ "tools/gpu/gl/angle/GLTestContext_angle.cpp" ]
     }
-    public_include_dirs += [ "third_party/vulkan" ]
+
     if (skia_use_vulkan) {
       sources += [ "tools/gpu/vk/VkTestContext.cpp" ]
       sources += [ "tools/gpu/vk/VkTestUtils.cpp" ]