fix for use of uninit variable

TBR=
BUG=skia:

Review URL: https://codereview.chromium.org/740463002
diff --git a/src/gpu/GrBitmapTextContext.cpp b/src/gpu/GrBitmapTextContext.cpp
index f22b760..2ff410e 100755
--- a/src/gpu/GrBitmapTextContext.cpp
+++ b/src/gpu/GrBitmapTextContext.cpp
@@ -548,12 +548,12 @@
         return;
     }
 
-    GrDrawState drawState;
-    drawState.setFromPaint(fPaint, SkMatrix::I(), fContext->getRenderTarget());
-
-    set_vertex_attributes(&drawState, fCurrMaskFormat);
-
     if (fCurrVertex > 0) {
+        GrDrawState drawState;
+        drawState.setFromPaint(fPaint, SkMatrix::I(), fContext->getRenderTarget());
+
+        set_vertex_attributes(&drawState, fCurrMaskFormat);
+
         // setup our sampler state for our text texture/atlas
         SkASSERT(SkIsAlign4(fCurrVertex));
         SkASSERT(fCurrTexture);