Vulkan: Rename PipelineDesc/Cache to Graphics&

PipelineDesc describes a Vertex-Fragment pipeline and PipelineCache (not
to be confused with vk::PipelineCache) implements a cache of such
pipeline objects.

In preparation for Compute support, these data structures are prefixed
with Graphics.

Bug: angleproject:2959
Change-Id: I9181586fb946b787216ca0b2ad6340f90c3ab55f
Reviewed-on: https://chromium-review.googlesource.com/c/1333971
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
diff --git a/src/libANGLE/renderer/vulkan/VertexArrayVk.cpp b/src/libANGLE/renderer/vulkan/VertexArrayVk.cpp
index 3748816..bb13ae8 100644
--- a/src/libANGLE/renderer/vulkan/VertexArrayVk.cpp
+++ b/src/libANGLE/renderer/vulkan/VertexArrayVk.cpp
@@ -367,7 +367,7 @@
     return angle::Result::Continue();
 }
 
-void VertexArrayVk::getPackedInputDescriptions(vk::PipelineDesc *pipelineDesc)
+void VertexArrayVk::getPackedInputDescriptions(vk::GraphicsPipelineDesc *pipelineDesc)
 {
     updatePackedInputDescriptions();
     pipelineDesc->updateVertexInputInfo(mPackedInputBindings, mPackedInputAttributes);