Remove DrawingMgr shims from GrContext

BUG=skia:4094

Review URL: https://codereview.chromium.org/1413673002
diff --git a/src/effects/SkGpuBlurUtils.cpp b/src/effects/SkGpuBlurUtils.cpp
index ec37505..f0c10c2 100644
--- a/src/effects/SkGpuBlurUtils.cpp
+++ b/src/effects/SkGpuBlurUtils.cpp
@@ -275,7 +275,7 @@
             SkRect dstRect = SkRect::MakeWH(srcRect.width(), srcRect.height());
 
             SkAutoTUnref<GrDrawContext> dstDrawContext(
-                                            context->drawContext(dstTexture->asRenderTarget()));
+                                             context->drawContext(dstTexture->asRenderTarget()));
             if (!dstDrawContext) {
                 return nullptr;
             }
@@ -309,7 +309,7 @@
             SkRect dstRect = SkRect::MakeWH(srcRect.width(), srcRect.height());
 
             SkAutoTUnref<GrDrawContext> dstDrawContext(
-                                             context->drawContext(dstTexture->asRenderTarget()));
+                                               context->drawContext(dstTexture->asRenderTarget()));
             if (!dstDrawContext) {
                 return nullptr;
             }
@@ -347,7 +347,7 @@
         scale_rect(&dstRect, (float) scaleFactorX, (float) scaleFactorY);
 
         SkAutoTUnref<GrDrawContext> dstDrawContext(
-                                            context->drawContext(dstTexture->asRenderTarget()));
+                                context->drawContext(dstTexture->asRenderTarget()));
         if (!dstDrawContext) {
             return nullptr;
         }