Make GrPaint have a variable sized array of color and coverage stages rather than a fixed size.

src/gpu/GrSWMaskHelper.cpp

Index: src/gpu/GrSWMaskHelper.cpp
diff --git a/src/gpu/GrSWMaskHelper.cpp b/src/gpu/GrSWMaskHelper.cpp
index 0fab55c361e7196fd271ff4f62b6b4df999fac51..c9f3989ebbb492c40cdb6850eac35bffc90adebe 100644
--- a/src/gpu/GrSWMaskHelper.cpp
+++ b/src/gpu/GrSWMaskHelper.cpp
@@ -192,12 +192,6 @@ void GrSWMaskHelper::DrawToTargetWithPathMask(GrTexture* texture,
         return;
     }
     GrDrawState::AutoRestoreEffects are(drawState);
-    enum {
-        // the SW path renderer shares this stage with glyph
-        // rendering (kGlyphMaskStage in GrTextContext)
-        // && edge rendering (kEdgeEffectStage in GrContext)
-        kPathMaskStage = GrPaint::kTotalStages,
-    };
 
     GrRect dstRect = GrRect::MakeLTRB(
                             SK_Scalar1 * rect.fLeft,