Sketch DM refactor.

dm/DMUtil.h

-#ifndef DMUtil_DEFINED
-#define DMUtil_DEFINED
-
-#include "SkBitmap.h"
-#include "SkCanvas.h"
-#include "SkString.h"
-#include "gm.h"
-
-class SkBBHFactory;
-
-// Small free functions used in more than one place in DM.
-
-namespace DM {
-
-// UnderJoin("a", "b") -> "a_b"
-SkString UnderJoin(const char* a, const char* b);
-
-// "foo_bar.skp" -> "foo-bar_skp"
-SkString FileToTaskName(SkString);
-
-// Draw gm to picture.
-SkPicture* RecordPicture(skiagm::GM* gm, SkBBHFactory* factory = NULL);
-
-// Allocate an empty bitmap with this size and depth.
-void AllocatePixels(SkColorType, int w, int h, SkBitmap* bitmap);
-// Allocate an empty bitmap the same size and depth as reference.
-void AllocatePixels(const SkBitmap& reference, SkBitmap* bitmap);
-
-// Draw picture to bitmap.
-void DrawPicture(const SkPicture& picture, SkBitmap* bitmap);
-
-// What is the maximum component difference in these bitmaps?
-unsigned MaxComponentDifference(const SkBitmap& a, const SkBitmap& b);
-
-// Are these identical bitmaps?
-bool BitmapsEqual(const SkBitmap& a, const SkBitmap& b);
-
-// Hook to modify canvas using global flag values (e.g. --matrix).
-void CanvasPreflight(SkCanvas*);
-
-}  // namespace DM
-
-#endif  // DMUtil_DEFINED