Move function to be static instead of anonymous namespace

TBR=bsalomon@google.com, jvanverth@google.com

BUG=skia:

Review URL: https://codereview.chromium.org/1057363004
diff --git a/src/gpu/GrGpu.cpp b/src/gpu/GrGpu.cpp
index 716c023..fdb098a 100644
--- a/src/gpu/GrGpu.cpp
+++ b/src/gpu/GrGpu.cpp
@@ -37,9 +37,7 @@
 
 ////////////////////////////////////////////////////////////////////////////////
 
-namespace {
-
-GrSurfaceOrigin resolve_origin(GrSurfaceOrigin origin, bool renderTarget) {
+static GrSurfaceOrigin resolve_origin(GrSurfaceOrigin origin, bool renderTarget) {
     // By default, GrRenderTargets are GL's normal orientation so that they
     // can be drawn to by the outside world without the client having
     // to render upside down.
@@ -50,8 +48,6 @@
     }
 }
 
-}
-
 GrTexture* GrGpu::createTexture(const GrSurfaceDesc& origDesc, bool budgeted,
                                 const void* srcData, size_t rowBytes) {
     GrSurfaceDesc desc = origDesc;