store info in basedevice, change getter to non-virtual const&

include/core/SkDevice.h

 /*
  * Copyright 2010 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkDevice_DEFINED
 #define SkDevice_DEFINED
 
@@ skipping 12 matching lines @@
 class SkMetaData;
 class SkRegion;
 class SkSpecialImage;
 class GrRenderTarget;
 
 class SK_API SkBaseDevice : public SkRefCnt {
 public:
     /**
      *  Construct a new device.
     */
-    explicit SkBaseDevice(const SkSurfaceProps&);
+    explicit SkBaseDevice(const SkImageInfo&, const SkSurfaceProps&);
     virtual ~SkBaseDevice();
 
     SkMetaData& getMetaData();
 
     /**
      *  Return ImageInfo for this device. If the canvas is not backed by pixels
      *  (cpu or gpu), then the info's ColorType will be kUnknown_SkColorType.
      */
-    virtual SkImageInfo imageInfo() const;
+    const SkImageInfo& imageInfo() const { return fInfo; }
 
     /**
      *  Return SurfaceProps for this device.
      */
     const SkSurfaceProps& surfaceProps() const {
         return fSurfaceProps;
     }
 
     /**
      *  Return the bounds of the device in the coordinate space of the root
@@ skipping 311 matching lines @@
 
     // just called by SkCanvas when built as a layer
     void setOrigin(int x, int y) { fOrigin.set(x, y); }
 
     /** Causes any deferred drawing to the device to be completed.
      */
     virtual void flush() {}
 
     virtual SkImageFilterCache* getImageFilterCache() { return NULL; }
 
+    friend class SkBitmapDevice;
+    void privateResize(int w, int h) {
+        *const_cast<SkImageInfo*>(&fInfo) = fInfo.makeWH(w, h);

[bsalomon, 2016/08/20 14:57:29]

why not just make it non-const? Also, there's a whole clique of friends up at
line 343.

+    }
+
     SkIPoint    fOrigin;
     SkMetaData* fMetaData;
-    SkSurfaceProps fSurfaceProps;
+    const SkImageInfo    fInfo;
+    const SkSurfaceProps fSurfaceProps;
 
 #ifdef SK_SUPPORT_LEGACY_ACCESSBITMAP
     SkBitmap    fLegacyBitmap;
 #endif
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif