Roll ahead shaderc API and update API usage as needed

Roll third_party/shaderc/ 4baa46a5d..68b6857ac (2 commits)

https://chromium.googlesource.com/external/github.com/google/shaderc/+log/4baa46a5d104..68b6857ac09d

$ git log 4baa46a5d..68b6857ac --date=short --no-merges --format='%ad %ae %s'
2019-09-18 rharrison Code hygiene work for spvc (#808)
2019-09-10 stevenperron Have update_build_version.py new parameter (#805)

Change-Id: I06e0f62a1443741e8ac09a84ff63ddd100f6a656
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/11341
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
diff --git a/DEPS b/DEPS
index b349259..59555ce 100644
--- a/DEPS
+++ b/DEPS
@@ -68,7 +68,7 @@
     'condition': 'dawn_standalone',
   },
   'third_party/shaderc': {
-    'url': '{chromium_git}/external/github.com/google/shaderc@4baa46a5d104f7de5aaee77b73b309d786e03288',
+    'url': '{chromium_git}/external/github.com/google/shaderc@68b6857ac09df396b51c740876654e9efca97f53',
     'condition': 'dawn_standalone',
   },
 
diff --git a/src/fuzzers/DawnSPIRVCrossFuzzer.h b/src/fuzzers/DawnSPIRVCrossFuzzer.h
index b60fd5d..49cfc97 100644
--- a/src/fuzzers/DawnSPIRVCrossFuzzer.h
+++ b/src/fuzzers/DawnSPIRVCrossFuzzer.h
@@ -16,7 +16,7 @@
 #include <functional>
 #include <vector>
 
-#include "shaderc/spvc.hpp"
+#include "spvc/spvc.hpp"
 
 namespace DawnSPIRVCrossFuzzer {