probable fix for asan bot

NOTREECHECKS=True
TBR=bsalomon@google.com
BUG=skia:

Review URL: https://codereview.chromium.org/956583002
diff --git a/include/gpu/GrClip.h b/include/gpu/GrClip.h
index ba26d5c..76cb46e 100644
--- a/include/gpu/GrClip.h
+++ b/include/gpu/GrClip.h
@@ -93,6 +93,7 @@
     }
 
     void setClipStack(const SkClipStack* clipStack, const SkIPoint* origin = NULL) {
+        this->reset();
         if (clipStack->isWideOpen()) {
             fClipType = kWideOpen_ClipType;
             fOrigin.setZero();
diff --git a/src/gpu/GrClip.cpp b/src/gpu/GrClip.cpp
index 15b1fbc8..1dc6edc 100644
--- a/src/gpu/GrClip.cpp
+++ b/src/gpu/GrClip.cpp
@@ -50,6 +50,6 @@
 }
 
 const GrClip& GrClip::WideOpen() {
-    static GrClip clip;
+    static const GrClip clip;
     return clip;
 }