Bundle common arguments to GrGradientEffect creation

I'm going to be adding more (to deal with color spaces), so trying to fix
this before it gets out of control.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2332213007

Committed: https://skia.googlesource.com/skia/+/f605c16a030d791a37f589e6bddd7158ba5d62cd
Review-Url: https://codereview.chromium.org/2332213007
diff --git a/src/effects/gradients/SkLinearGradient.cpp b/src/effects/gradients/SkLinearGradient.cpp
index 98b621e..a93235d 100644
--- a/src/effects/gradients/SkLinearGradient.cpp
+++ b/src/effects/gradients/SkLinearGradient.cpp
@@ -351,11 +351,8 @@
 public:
     class GLSLLinearProcessor;
 
-    static sk_sp<GrFragmentProcessor> Make(GrContext* ctx,
-                                           const SkLinearGradient& shader,
-                                           const SkMatrix& matrix,
-                                           SkShader::TileMode tm) {
-        return sk_sp<GrFragmentProcessor>(new GrLinearGradient(ctx, shader, matrix, tm));
+    static sk_sp<GrFragmentProcessor> Make(const CreateArgs& args) {
+        return sk_sp<GrFragmentProcessor>(new GrLinearGradient(args));
     }
 
     virtual ~GrLinearGradient() { }
@@ -363,11 +360,8 @@
     const char* name() const override { return "Linear Gradient"; }
 
 private:
-    GrLinearGradient(GrContext* ctx,
-                     const SkLinearGradient& shader,
-                     const SkMatrix& matrix,
-                     SkShader::TileMode tm)
-        : INHERITED(ctx, shader, matrix, tm) {
+    GrLinearGradient(const CreateArgs& args)
+        : INHERITED(args) {
         this->initClassID<GrLinearGradient>();
     }
 
@@ -467,8 +461,8 @@
     }
     matrix.postConcat(fPtsToUnit);
 
-    sk_sp<GrFragmentProcessor> inner(
-        GrLinearGradient::Make(args.fContext, *this, matrix, fTileMode));
+    sk_sp<GrFragmentProcessor> inner(GrLinearGradient::Make(
+        GrGradientEffect::CreateArgs(args.fContext, this, &matrix, fTileMode)));
     return GrFragmentProcessor::MulOutputByInputAlpha(std::move(inner));
 }