Use DAWN_VULKAN_DEPS_DIR consistently.

Several of the CMake variables were creating the vulkan-deps folder from
the `THIRD_PARTY_DIR` instead of the provided `VULKAN_DEPS_DIR`.

Change-Id: Id620485b17f833cedbb6403d0f01f0ceba51b660
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/126761
Kokoro: Ben Clayton <bclayton@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
diff --git a/CMakeLists.txt b/CMakeLists.txt
index ece7a2c..346bfe2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -178,15 +178,17 @@
 set(ABSL_PROPAGATE_CXX_STD ON)
 
 set_if_not_defined(DAWN_THIRD_PARTY_DIR "${Dawn_SOURCE_DIR}/third_party" "Directory in which to find third-party dependencies.")
+set_if_not_defined(DAWN_VULKAN_DEPS_DIR "${DAWN_THIRD_PARTY_DIR}/vulkan-deps" "Directory in which to find vulkan-deps")
+
 set_if_not_defined(DAWN_ABSEIL_DIR "${DAWN_THIRD_PARTY_DIR}/abseil-cpp" "Directory in which to find Abseil")
 set_if_not_defined(DAWN_GLFW_DIR "${DAWN_THIRD_PARTY_DIR}/glfw" "Directory in which to find GLFW")
 set_if_not_defined(DAWN_JINJA2_DIR "${DAWN_THIRD_PARTY_DIR}/jinja2" "Directory in which to find Jinja2")
 set_if_not_defined(DAWN_MARKUPSAFE_DIR "${DAWN_THIRD_PARTY_DIR}/markupsafe" "Directory in which to find MarkupSafe")
 set_if_not_defined(DAWN_KHRONOS_DIR "${DAWN_THIRD_PARTY_DIR}/khronos" "Directory in which to find Khronos GL headers")
-set_if_not_defined(DAWN_SPIRV_HEADERS_DIR "${DAWN_THIRD_PARTY_DIR}/vulkan-deps/spirv-headers/src" "Directory in which to find SPIRV-Headers")
-set_if_not_defined(DAWN_SPIRV_TOOLS_DIR "${DAWN_THIRD_PARTY_DIR}/vulkan-deps/spirv-tools/src" "Directory in which to find SPIRV-Tools")
 set_if_not_defined(DAWN_SWIFTSHADER_DIR "${DAWN_THIRD_PARTY_DIR}/swiftshader" "Directory in which to find swiftshader")
-set_if_not_defined(DAWN_VULKAN_DEPS_DIR "${DAWN_THIRD_PARTY_DIR}/vulkan-deps" "Directory in which to find vulkan-deps")
+
+set_if_not_defined(DAWN_SPIRV_TOOLS_DIR "${DAWN_VULKAN_DEPS_DIR}/spirv-tools/src" "Directory in which to find SPIRV-Tools")
+set_if_not_defined(DAWN_SPIRV_HEADERS_DIR "${DAWN_VULKAN_DEPS_DIR}/spirv-headers/src" "Directory in which to find SPIRV-Headers")
 set_if_not_defined(DAWN_VULKAN_HEADERS_DIR "${DAWN_VULKAN_DEPS_DIR}/vulkan-headers/src" "Directory in which to find Vulkan-Headers")
 set_if_not_defined(DAWN_VULKAN_TOOLS_DIR "${DAWN_VULKAN_DEPS_DIR}/vulkan-tools/src" "Directory in which to find Vulkan-Tools")