Vulkan: Clean up object releasing APIs.

This cleans up the confusing releaseResource/releaseObject pair in the
RendererVk class. It also makes getQueueSerial private in ResourceVk
but keeps a public isResourceInUse API for external use.

Bug: angleproject:2539
Change-Id: I6b4f24db16e36130a85ef03fc2c3b26d8d9e1fba
Reviewed-on: https://chromium-review.googlesource.com/1069291
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Frank Henigman <fjhenigman@chromium.org>
diff --git a/src/libANGLE/renderer/vulkan/FramebufferVk.cpp b/src/libANGLE/renderer/vulkan/FramebufferVk.cpp
index eb9a722..6ecdd6c 100644
--- a/src/libANGLE/renderer/vulkan/FramebufferVk.cpp
+++ b/src/libANGLE/renderer/vulkan/FramebufferVk.cpp
@@ -76,7 +76,7 @@
 {
     ContextVk *contextVk = vk::GetImpl(context);
     RendererVk *renderer = contextVk->getRenderer();
-    renderer->releaseResource(*this, &mFramebuffer);
+    renderer->releaseObject(getStoredQueueSerial(), &mFramebuffer);
 
     mReadPixelsBuffer.destroy(contextVk->getDevice());
 }
@@ -388,7 +388,7 @@
         mActiveColorComponentMasks[2].any(), mActiveColorComponentMasks[3].any());
 
     mRenderPassDesc.reset();
-    renderer->releaseResource(*this, &mFramebuffer);
+    renderer->releaseObject(getStoredQueueSerial(), &mFramebuffer);
 
     // Will freeze the current set of dependencies on this FBO. The next time we render we will
     // create a new entry in the command graph.