Vulkan: Add shader handling for textures.

BUG=angleproject:2167

Change-Id: I33940288331a23b940753795e5e43b8cabcb87f5
Reviewed-on: https://chromium-review.googlesource.com/732189
Reviewed-by: Frank Henigman <fjhenigman@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
diff --git a/src/libANGLE/renderer/vulkan/ProgramVk.cpp b/src/libANGLE/renderer/vulkan/ProgramVk.cpp
index efb8625..13a157a 100644
--- a/src/libANGLE/renderer/vulkan/ProgramVk.cpp
+++ b/src/libANGLE/renderer/vulkan/ProgramVk.cpp
@@ -272,7 +272,11 @@
         const auto &location = locations[locationIndex];
         if (location.used() && !location.ignored)
         {
-            const auto &uniform     = uniforms[location.index];
+            const auto &uniform = uniforms[location.index];
+
+            if (uniform.isSampler())
+                continue;
+
             std::string uniformName = uniform.name;
             if (uniform.isArray())
             {