Vulkan: Let XFB's BufferHelper keep SharedDescriptorSetCacheKey

instead of BufferBlock. Unlike uniform buffers which uses
VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC, the descriptorSet for
transform feedback buffers also have the buffer offset baked in, so it
is not helpful to use BufferBlock's serial in the cache key.  This CL
changes to use BufferHelper's serial for cache key. With this we can
also let BufferHelper keep the SharedDescriptorSetCacheKey instead of
store it in the BufferBlock. In the case that BufferHelper gets
destroyed and recreated, the SharedDescriptorSetCacheKey will also get
destroyed. Right now because we cache BufferBlock serial, the
SharedDescriptorSetCacheKey will not be destroyed even though
BufferHelper is destroyed and there is very rare case that it can be
reused, thus causing BufferBlock's SharedDescriptorSetCacheKey queue
keep increasing, which causes perf issue.

Bug: b/384839847
Change-Id: I76b8f0d56486079740cca302e8b14a04a6e24074
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/6115111
Reviewed-by: mohan maiya <m.maiya@samsung.com>
Commit-Queue: Yuxin Hu <yuxinhu@google.com>
Auto-Submit: Charlie Lao <cclao@google.com>
Reviewed-by: Yuxin Hu <yuxinhu@google.com>

src/libANGLE/renderer/vulkan/TransformFeedbackVk.cpp

@@ -266,7 +266,6 @@ void TransformFeedbackVk::updateTransformFeedbackDescriptorDesc(
     vk::DescriptorSetDescBuilder *builder) const
 {
     size_t xfbBufferCount = executable.getTransformFeedbackBufferCount();
-
     for (uint32_t bufferIndex = 0; bufferIndex < xfbBufferCount; ++bufferIndex)
     {
         if (mBufferHelpers[bufferIndex] && activeUnpaused)
@@ -291,14 +290,9 @@ void TransformFeedbackVk::onNewDescriptorSet(const gl::ProgramExecutable &execut
     size_t xfbBufferCount = executable.getTransformFeedbackBufferCount();
     for (uint32_t bufferIndex = 0; bufferIndex < xfbBufferCount; ++bufferIndex)
     {
-        const gl::OffsetBindingPointer<gl::Buffer> &binding = mState.getIndexedBuffer(bufferIndex);
-        if (binding.get())
+        if (mBufferHelpers[bufferIndex])
         {
-            BufferVk *bufferVk = vk::GetImpl(binding.get());
-            if (bufferVk->getBuffer().valid())
-            {
-                bufferVk->getBuffer().getBufferBlock()->onNewDescriptorSet(sharedCacheKey);
-            }
+            mBufferHelpers[bufferIndex]->onNewDescriptorSet(sharedCacheKey);
         }
     }
 }

src/libANGLE/renderer/vulkan/vk_cache_utils.cpp

@@ -6292,7 +6292,7 @@ void DescriptorSetDescBuilder::updateTransformFeedbackBuffer(
 
     uint32_t infoIndex = writeDescriptorDescs[baseBinding].descriptorInfoIndex + xfbBufferIndex;
     DescriptorInfoDesc &infoDesc   = mDesc.getInfoDesc(infoIndex);
-    infoDesc.samplerOrBufferSerial = bufferHelper.getBlockSerial().getValue();
+    infoDesc.samplerOrBufferSerial = bufferHelper.getBufferSerial().getValue();
     SetBitField(infoDesc.imageViewSerialOrOffset, alignedOffset);
     SetBitField(infoDesc.imageLayoutOrRange, adjustedRange);
     infoDesc.imageSubresourceRange = 0;