Add support for dummy draws for Vulkan webview and texture views.

Test: manual testing
Change-Id: Iaec8c3a34367673c281665ff6c6e97d1ce532265
diff --git a/libs/hwui/renderthread/VulkanManager.cpp b/libs/hwui/renderthread/VulkanManager.cpp
index 68c04af..2b90744 100644
--- a/libs/hwui/renderthread/VulkanManager.cpp
+++ b/libs/hwui/renderthread/VulkanManager.cpp
@@ -19,6 +19,7 @@
 #include "DeviceInfo.h"
 #include "Properties.h"
 #include "RenderThread.h"
+#include "renderstate/RenderState.h"
 
 #include <GrContext.h>
 #include <GrTypes.h>
@@ -37,10 +38,14 @@
 void VulkanManager::destroy() {
     if (!hasVkContext()) return;
 
+    mRenderThread.renderState().onVkContextDestroyed();
+    mRenderThread.setGrContext(nullptr);
+
     if (VK_NULL_HANDLE != mCommandPool) {
         mDestroyCommandPool(mBackendContext->fDevice, mCommandPool, nullptr);
         mCommandPool = VK_NULL_HANDLE;
     }
+    mBackendContext.reset();
 }
 
 void VulkanManager::initialize() {
@@ -105,6 +110,8 @@
     if (Properties::enablePartialUpdates && Properties::useBufferAge) {
         mSwapBehavior = SwapBehavior::BufferAge;
     }
+
+    mRenderThread.renderState().onVkContextCreated();
 }
 
 // Returns the next BackbufferInfo to use for the next draw. The function will make sure all
@@ -156,6 +163,9 @@
         if (!createSwapchain(surface)) {
             return nullptr;
         }
+        backbuffer = getAvailableBackbuffer(surface);
+        res = mResetFences(mBackendContext->fDevice, 2, backbuffer->mUsageFences);
+        SkASSERT(VK_SUCCESS == res);
 
         // acquire the image
         res = mAcquireNextImageKHR(mBackendContext->fDevice, surface->mSwapchain, UINT64_MAX,