effects: Replaces uses of GrAssert with SkASSERT.

This is the first step on migrating from GrAssert to SkASSERT as requested by
Brian.

R=bsalomon@google.com, robertphillips@google.com, scroggo@google.com

Author: tfarina@chromium.org

Review URL: https://chromiumcodereview.appspot.com/22418006

git-svn-id: http://skia.googlecode.com/svn/trunk@10706 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/effects/gradients/SkGradientShader.cpp b/src/effects/gradients/SkGradientShader.cpp
index de43b69..4e528b5 100644
--- a/src/effects/gradients/SkGradientShader.cpp
+++ b/src/effects/gradients/SkGradientShader.cpp
@@ -910,7 +910,7 @@
     desc.fContext = ctx;
     desc.fConfig = SkBitmapConfig2GrPixelConfig(bitmap.config());
     fAtlas = GrTextureStripAtlas::GetAtlas(desc);
-    GrAssert(NULL != fAtlas);
+    SkASSERT(NULL != fAtlas);
 
     // We always filter the gradient table. Each table is one row of a texture, so always y-clamp.
     GrTextureParams params;