SkPerlinNoiseShader::CreateTubulenceNoise() is misspelled

Add missing 'r'.

BUG=skia:2329
R=bsalomon@google.com, hcm@google.com, sugoi@chromium.org

Author: siglesias@igalia.com

Review URL: https://codereview.chromium.org/207543008

git-svn-id: http://skia.googlecode.com/svn/trunk@14008 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gm/perlinnoise.cpp b/gm/perlinnoise.cpp
index 164c021..cce5b02 100644
--- a/gm/perlinnoise.cpp
+++ b/gm/perlinnoise.cpp
@@ -43,7 +43,7 @@
         SkShader* shader = (type == SkPerlinNoiseShader::kFractalNoise_Type) ?
             SkPerlinNoiseShader::CreateFractalNoise(baseFrequencyX, baseFrequencyY, numOctaves,
                                                    seed, stitchTiles ? &fSize : NULL) :
-            SkPerlinNoiseShader::CreateTubulence(baseFrequencyX, baseFrequencyY, numOctaves,
+            SkPerlinNoiseShader::CreateTurbulence(baseFrequencyX, baseFrequencyY, numOctaves,
                                                 seed, stitchTiles ? &fSize : NULL);
         SkPaint paint;
         paint.setShader(shader)->unref();