Extract gpu line dashing to GrDashLinePathRenderer

src/gpu/GrDashLinePathRenderer.cpp

+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GrDashLinePathRenderer.h"
+
+#include "GrGpu.h"
+#include "effects/GrDashingEffect.h"
+
+GrDashLinePathRenderer::GrDashLinePathRenderer(GrContext* context)
+        : fGpu(SkRef(context->getGpu())) {
+}
+
+GrDashLinePathRenderer::~GrDashLinePathRenderer() {
+}
+
+bool GrDashLinePathRenderer::canDrawPath(const GrDrawTarget* target,
+                                         const GrPipelineBuilder* pipelineBuilder,
+                                         const SkMatrix& viewMatrix,
+                                         const SkPath& path,
+                                         const GrStrokeInfo& stroke,
+                                         bool antiAlias) const {
+    SkPoint pts[2];
+    if (stroke.isDashed() && path.isLine(pts)) {
+        return GrDashingEffect::CanDrawDashLine(pts, stroke, viewMatrix);
+    }
+    return false;
+}
+
+bool GrDashLinePathRenderer::onDrawPath(GrDrawTarget* target,
+                                        GrPipelineBuilder* pipelineBuilder,
+                                        GrColor color,
+                                        const SkMatrix& viewMatrix,
+                                        const SkPath& path,
+                                        const GrStrokeInfo& stroke,
+                                        bool useAA) {
+    SkPoint pts[2];
+    SkAssertResult(path.isLine(pts));
+    return GrDashingEffect::DrawDashLine(fGpu, target, pipelineBuilder, color,
+                                         viewMatrix, pts, useAA, stroke);
+}