Move GrVkSecondaryCBDrawContext header into src to hide it.

We want to hide this API from general public use. Chromium can dig into
skia to include it as it does with other Skia API's that are in src

Bug: skia:
Change-Id: I00dc36d181237ea0785eefb31ad6c2d4e50e3c68
Reviewed-on: https://skia-review.googlesource.com/c/180648
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
diff --git a/gn/gpu.gni b/gn/gpu.gni
index a8a0602..b8ce2ef 100644
--- a/gn/gpu.gni
+++ b/gn/gpu.gni
@@ -572,7 +572,6 @@
   "$_include/gpu/vk/GrVkBackendContext.h",
   "$_include/gpu/vk/GrVkExtensions.h",
   "$_include/gpu/vk/GrVkMemoryAllocator.h",
-  "$_include/gpu/vk/GrVkSecondaryCBDrawContext.h",
   "$_include/gpu/vk/GrVkTypes.h",
   "$_include/gpu/vk/GrVkVulkan.h",
   "$_include/private/GrVkTypesPriv.h",
@@ -639,6 +638,7 @@
   "$_src/gpu/vk/GrVkSamplerYcbcrConversion.cpp",
   "$_src/gpu/vk/GrVkSamplerYcbcrConversion.h",
   "$_src/gpu/vk/GrVkSecondaryCBDrawContext.cpp",
+  "$_src/gpu/vk/GrVkSecondaryCBDrawContext.h",
   "$_src/gpu/vk/GrVkSemaphore.cpp",
   "$_src/gpu/vk/GrVkSemaphore.h",
   "$_src/gpu/vk/GrVkStencilAttachment.cpp",
diff --git a/include/gpu/vk/GrVkSecondaryCBDrawContext.h b/src/gpu/vk/GrVkSecondaryCBDrawContext.h
similarity index 94%
rename from include/gpu/vk/GrVkSecondaryCBDrawContext.h
rename to src/gpu/vk/GrVkSecondaryCBDrawContext.h
index 7863181..6a47775 100644
--- a/include/gpu/vk/GrVkSecondaryCBDrawContext.h
+++ b/src/gpu/vk/GrVkSecondaryCBDrawContext.h
@@ -21,6 +21,12 @@
 class SkSurfaceProps;
 
 /**
+ * This class is a private header that is intended to only be used inside of Chromium. This requires
+ * Chromium to burrow in and include this specifically since it is not part of skia's public include
+ * directory.
+ */
+
+/**
  * This class is used to draw into an external Vulkan secondary command buffer that is imported
  * by the client. The secondary command buffer that gets imported must already have had begin called
  * on it with VK_COMMAND_BUFFER_USAGE_RENDER_PASS_CONTINUE_BIT. Thus any draws to the imported