Use texture strip atlas for color table filter

src/gpu/effects/GrTextureStripAtlas.h

Index: src/gpu/effects/GrTextureStripAtlas.h
diff --git a/src/gpu/effects/GrTextureStripAtlas.h b/src/gpu/effects/GrTextureStripAtlas.h
index 58539fc0acb8730deaf068971a129f86c5a52ca6..80b33bbac4bd7504246d481bea440b1b512aab30 100644
--- a/src/gpu/effects/GrTextureStripAtlas.h
+++ b/src/gpu/effects/GrTextureStripAtlas.h
@@ -61,11 +61,11 @@ public:
      *       texture2D(sampler, vec2(x, yOffset + y * scaleFactor))
      *
      * Where yOffset, returned by getYOffset(), is the offset to the start of the row within the
-     * atlas and scaleFactor, returned by getVerticalScaleFactor(), is the y-scale of the row,
-     * relative to the height of the overall atlas texture.
+     * atlas and scaleFactor, returned by getNormalizedTexelHeight, is the normalized height of
+     * one texel row.
      */
     SkScalar getYOffset(int row) const { return SkIntToScalar(row) / fNumRows; }
-    SkScalar getVerticalScaleFactor() const { return SkIntToScalar(fDesc.fRowHeight) / fDesc.fHeight; }
+    SkScalar getNormalizedTexelHeight() const { return fNormalizedYHeight; }
 
     GrContext* getContext() const { return fDesc.fContext; }
     GrTexture* getTexture() const { return fTexture; }
@@ -168,6 +168,8 @@ private:
     const uint16_t fNumRows;
     GrTexture* fTexture;
 
+    SkScalar fNormalizedYHeight;
+
     // Array of AtlasRows which store the state of all our rows. Stored in a contiguous array, in
     // order that they appear in our texture, this means we can subtract this pointer from a row
     // pointer to get its index in the texture, and can save storing a row number in AtlasRow.