Fix a crash on stroking empty paths with nv_path_rendering enabled

src/gpu/gl/GrGLPath.cpp

 
 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrGLPath.h"
 #include "GrGpuGL.h"
@@ skipping 41 matching lines @@
 
     GrAssert(verb >= 0 && (size_t)verb < GR_ARRAY_COUNT(gTable));
     return gTable[verb];
 }
 #endif
 }
 
 static const bool kIsWrapped = false; // The constructor creates the GL path object.
 
 GrGLPath::GrGLPath(GrGpuGL* gpu, const SkPath& path) : INHERITED(gpu, kIsWrapped) {
-    GL_CALL_RET(fPathID, GenPaths(1));
-    SkPath::Iter iter(path, true);
-
-    SkSTArray<16, GrGLubyte, true> pathCommands;
 #ifndef SK_SCALAR_IS_FLOAT
     GrCrash("Assumes scalar is float.");
 #endif
+    SkASSERT(!path.isEmpty());
+
+    GL_CALL_RET(fPathID, GenPaths(1));
+
+    SkSTArray<16, GrGLubyte, true> pathCommands;
     SkSTArray<16, SkPoint, true> pathPoints;
 
     int verbCnt = path.countVerbs();
     int pointCnt = path.countPoints();
     pathCommands.resize_back(verbCnt);
     pathPoints.resize_back(pointCnt);
 
     // TODO: Direct access to path points since we could pass them on directly.
     path.getPoints(&pathPoints[0], pointCnt);
     path.getVerbs(&pathCommands[0], verbCnt);
@@ skipping 23 matching lines @@
     }
 
     INHERITED::onRelease();
 }
 
 void GrGLPath::onAbandon() {
     fPathID = 0;
 
     INHERITED::onAbandon();
 }