Respecify SkCanvas::drawArc, consolidate conversion to SkPath, add GM for oddball drawArcs

src/gpu/GrDrawContext.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 "GrBatchTest.h"
 #include "GrColor.h"
 #include "GrDrawContext.h"
@@ skipping 1005 matching lines @@
                                                                        useCenter,
                                                                        style,
                                                                        shaderCaps));
         if (batch) {
             GrPipelineBuilder pipelineBuilder(paint, useHWAA);
             this->getDrawTarget()->drawBatch(pipelineBuilder, this, clip, batch);
             return;
         }
     }
     SkPath path;
-    path.setIsVolatile(true);
-    if (useCenter) {
-        path.moveTo(oval.centerX(), oval.centerY());
-    }
-    path.arcTo(oval, startAngle, sweepAngle, !useCenter);
-    if (useCenter) {
-        path.close();
-    }
+    SkPathPriv::CreateDrawArcPath(&path, oval, startAngle, sweepAngle, useCenter,
+                                  style.isSimpleFill());
     this->internalDrawPath(clip, paint, viewMatrix, path, style);
     return;
 }
 
 void GrDrawContext::drawImageLattice(const GrClip& clip,
                                      const GrPaint& paint,
                                      const SkMatrix& viewMatrix,
                                      int imageWidth,
                                      int imageHeight,
                                      std::unique_ptr<SkLatticeIter> iter,
@@ skipping 301 matching lines @@
 
 void GrDrawContext::drawBatch(const GrPipelineBuilder& pipelineBuilder, const GrClip& clip,
                               GrDrawBatch* batch) {
     ASSERT_SINGLE_OWNER
     RETURN_IF_ABANDONED
     SkDEBUGCODE(this->validate();)
     GR_AUDIT_TRAIL_AUTO_FRAME(fAuditTrail, "GrDrawContext::drawBatch");
 
     this->getDrawTarget()->drawBatch(pipelineBuilder, this, clip, batch);
 }