Vulkan: Fix perftests null driver.

We needed to set the CWD for the mock ICD as well.

Bug: angleproject:2604
Change-Id: I1d285c478030056360fd2dceca78e231ac321219
Reviewed-on: https://chromium-review.googlesource.com/1169426
Reviewed-by: Omar El Sheikh <theoking@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
diff --git a/src/libANGLE/renderer/vulkan/RendererVk.cpp b/src/libANGLE/renderer/vulkan/RendererVk.cpp
index abd9f6f..d748b03 100644
--- a/src/libANGLE/renderer/vulkan/RendererVk.cpp
+++ b/src/libANGLE/renderer/vulkan/RendererVk.cpp
@@ -136,13 +136,14 @@
                 mEnableMockICD = false;
             }
         }
-        if (mEnableValidationLayers)
+        if (mEnableValidationLayers || mEnableMockICD)
         {
             const auto &cwd = angle::GetCWD();
             if (!cwd.valid())
             {
                 ERR() << "Error getting CWD for Vulkan layers init.";
                 mEnableValidationLayers = false;
+                mEnableMockICD          = false;
             }
             else
             {
@@ -153,6 +154,7 @@
                 {
                     ERR() << "Error setting CWD for Vulkan layers init.";
                     mEnableValidationLayers = false;
+                    mEnableMockICD          = false;
                 }
             }
         }