Update iOS to new SkSurface interface

experimental/iOSSampleApp/SkSampleUIView.mm

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #import "SkSampleUIView.h"
 
 //#define SKGL_CONFIG         kEAGLColorFormatRGB565
@@ skipping 105 matching lines @@
         fCurRenderTarget = NULL;
 #endif
         win->release();
         fBackend = SampleWindow::kNone_BackEndType;
     }
 
     SkSurface* createSurface(SampleWindow::DeviceType dType, SampleWindow* win) override{
 #if SK_SUPPORT_GPU
         if (SampleWindow::IsGpuDeviceType(dType) && fCurContext) {
             SkSurfaceProps props(win->getSurfaceProps());
-            return SkSurface::NewRenderTargetDirect(fCurRenderTarget, &props);
+            return SkSurface::MakeRenderTargetDirect(fCurRenderTarget,
+                                                     sk_ref_sp(win->info().colorSpace()),
+                                                     &props).release();
         }
 #endif
-        return NULL;
+        return nullptr;
     }
 
     virtual void publishCanvas(SampleWindow::DeviceType dType,
                                SkCanvas* canvas,
                                SampleWindow* win) override {
 #if SK_SUPPORT_GPU
         if (NULL != fCurContext) {
             fCurContext->flush();
         }
 #endif
@@ skipping 345 matching lines @@
     glBindRenderbuffer(GL_RENDERBUFFER, fGL.fRenderbuffer);
     glGetRenderbufferParameteriv(GL_RENDERBUFFER,
                                  GL_RENDERBUFFER_STENCIL_SIZE,
                                  &info->fStencilBits);
     glGetRenderbufferParameteriv(GL_RENDERBUFFER,
                                  GL_RENDERBUFFER_SAMPLES_APPLE,
                                  &info->fSampleCount);
 }
 
 @end