Remove DrawingMgr shims from GrContext

src/gpu/GrContext.cpp

Index: src/gpu/GrContext.cpp
diff --git a/src/gpu/GrContext.cpp b/src/gpu/GrContext.cpp
index a691da7de326360c8c69dd2f81c6c0b68d38235c..c6a45fa99cf3568592388b787dcd614e0b679b36 100644
--- a/src/gpu/GrContext.cpp
+++ b/src/gpu/GrContext.cpp
@@ -152,12 +152,12 @@ GrDrawTarget* GrContext::DrawingMgr::newDrawTarget(GrRenderTarget* rt) {
 }
 
 GrDrawContext* GrContext::DrawingMgr::drawContext(GrRenderTarget* rt, 
-                                                  const SkSurfaceProps* surfaceProps) {
+                                                  const SkSurfaceProps* surfaceProps) const {
     if (this->abandoned()) {
         return nullptr;
     }
 
-    return new GrDrawContext(fContext, rt, surfaceProps);
+    return new GrDrawContext(const_cast<DrawingMgr*>(this), rt, surfaceProps);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -456,7 +456,7 @@ bool GrContext::writeSurfacePixels(GrSurface* surface,
             }
             SkMatrix matrix;
             matrix.setTranslate(SkIntToScalar(left), SkIntToScalar(top));
-            SkAutoTUnref<GrDrawContext> drawContext(this->drawContext(renderTarget));
+            SkAutoTUnref<GrDrawContext> drawContext(fDrawingMgr.drawContext(renderTarget));
             if (!drawContext) {
                 return false;
             }
@@ -568,7 +568,8 @@ bool GrContext::readSurfacePixels(GrSurface* src,
             if (fp) {
                 paint.addColorFragmentProcessor(fp);
                 SkRect rect = SkRect::MakeWH(SkIntToScalar(width), SkIntToScalar(height));
-                SkAutoTUnref<GrDrawContext> drawContext(this->drawContext(temp->asRenderTarget()));
+                SkAutoTUnref<GrDrawContext> drawContext(
+                                                fDrawingMgr.drawContext(temp->asRenderTarget()));
                 drawContext->drawRect(GrClip::WideOpen(), paint, SkMatrix::I(), rect, nullptr);
                 surfaceToRead.reset(SkRef(temp.get()));
                 left = 0;
@@ -643,7 +644,7 @@ void GrContext::copySurface(GrSurface* dst, GrSurface* src, const SkIRect& srcRe
         return;
     }
 
-    SkAutoTUnref<GrDrawContext> drawContext(this->drawContext(dst->asRenderTarget()));
+    SkAutoTUnref<GrDrawContext> drawContext(fDrawingMgr.drawContext(dst->asRenderTarget()));
     if (!drawContext) {
         return;
     }