use some helper Make functions to initialize SkImageInfo

gm/srcmode.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gm.h"
 #include "SkCanvas.h"
 #include "SkGradientShader.h"
@@ skipping 99 matching lines @@
                     canvas->translate(W * 5 / 4, 0);
                 }
             }
             canvas->restore();
             canvas->translate(0, (H * 5 / 4) * SK_ARRAY_COUNT(procs));
         }
     }
 
     static SkSurface* compat_surface(SkCanvas* canvas, const SkISize& size,
                                      bool skipGPU) {
-        SkImageInfo info = {
-            size.width(),
-            size.height(),
-            kPMColor_SkColorType,
-            kPremul_SkAlphaType
-        };
+        SkImageInfo info = SkImageInfo::MakeN32Premul(size);
 #if SK_SUPPORT_GPU
         SkBaseDevice* dev = canvas->getDevice();
         if (!skipGPU && dev->accessRenderTarget()) {
             SkGpuDevice* gd = (SkGpuDevice*)dev;
             GrContext* ctx = gd->context();
             return SkSurface::NewRenderTarget(ctx, info, 0);
         }
 #endif
         return SkSurface::NewRaster(info);
     }
 
     virtual void onDraw(SkCanvas* canvas) {
         SkAutoTUnref<SkSurface> surf(compat_surface(canvas, this->getISize(),
                                                     this->isCanvasDeferred()));
         surf->getCanvas()->drawColor(SK_ColorWHITE);
         this->drawContent(surf->getCanvas());
         surf->draw(canvas, 0, 0, NULL);
     }
 
 private:
     typedef skiagm::GM INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 DEF_GM(return new SrcModeGM;)