Fix GrTextureOp to check the correct cap for multitexturing

Change-Id: I276dff12055b046423ed261d014bc58302fb1347
Reviewed-on: https://skia-review.googlesource.com/70680
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/ops/GrTextureOp.cpp b/src/gpu/ops/GrTextureOp.cpp
index a03b40e..410257c 100644
--- a/src/gpu/ops/GrTextureOp.cpp
+++ b/src/gpu/ops/GrTextureOp.cpp
@@ -513,7 +513,7 @@
                 }
             }
         }
-        int actualMaxTextures = SkTMin(caps.maxFragmentImageStorages(), kMaxTextures);
+        int actualMaxTextures = SkTMin(caps.maxFragmentSamplers(), kMaxTextures);
         int newProxyCnt = that->fProxyCnt - sharedProxyCnt;
         if (newProxyCnt + fProxyCnt > actualMaxTextures) {
             return -1;