Code refactoring: replace NULL by nullptr for pointers.

This is the frist change to replace NULL by nullptr.
It handles the initialization and assignment for pointers.

BUG=angleproject:2001

Change-Id: I6d4bb198a72e38b867cd2f65a6e6f2f61339a0b5
Reviewed-on: https://chromium-review.googlesource.com/481600
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
diff --git a/src/compiler/translator/ShaderLang.cpp b/src/compiler/translator/ShaderLang.cpp
index 11b83f3..9ac335a 100644
--- a/src/compiler/translator/ShaderLang.cpp
+++ b/src/compiler/translator/ShaderLang.cpp
@@ -182,7 +182,7 @@
     resources->MaxViewsOVR = 2;
 
     // Disable name hashing by default.
-    resources->HashFunction = NULL;
+    resources->HashFunction = nullptr;
 
     resources->ArrayIndexClampingStrategy = SH_CLAMP_WITH_CLAMP_INTRINSIC;