Revert of Revert of Revert of Change device creation to see the (optional) layer-paint

include/core/SkDevice.h

Index: include/core/SkDevice.h
diff --git a/include/core/SkDevice.h b/include/core/SkDevice.h
index 684a08404c02f036184fc38b7c7d866ece8cea42..c7c5c30b3a03fd19909db1d5ca2d861c9ffc278e 100644
--- a/include/core/SkDevice.h
+++ b/include/core/SkDevice.h
@@ -125,9 +125,10 @@
     };
 
 protected:
-    enum TileUsage {
-        kPossible_TileUsage,    //!< the created device may be drawn tiled
-        kNever_TileUsage,       //!< the created device will never be drawn tiled
+    enum Usage {
+       kGeneral_Usage,
+       kSaveLayer_Usage,  // <! internal use only
+       kImageFilter_Usage // <! internal use only
     };
 
     struct TextFlags {
@@ -230,7 +231,7 @@
     virtual void drawPatch(const SkDraw&, const SkPoint cubics[12], const SkColor colors[4],
                            const SkPoint texCoords[4], SkXfermode* xmode, const SkPaint& paint);
     /** The SkDevice passed will be an SkDevice which was returned by a call to
-        onCreateDevice on this device with kNeverTile_TileExpectation.
+        onCreateCompatibleDevice on this device with kSaveLayer_Usage.
      */
     virtual void drawDevice(const SkDraw&, SkBaseDevice*, int x, int y,
                             const SkPaint&) = 0;
@@ -252,6 +253,14 @@
     */
     virtual void lockPixels() {}
     virtual void unlockPixels() {}
+
+    /**
+     *  Returns true if the device allows processing of this imagefilter. If
+     *  false is returned, then the filter is ignored. This may happen for
+     *  some subclasses that do not support pixel manipulations after drawing
+     *  has occurred (e.g. printing). The default implementation returns true.
+     */
+    virtual bool allowImageFilter(const SkImageFilter*) { return true; }
 
     /**
      *  Override and return true for filters that the device can handle
@@ -327,38 +336,23 @@
                                           const SkPaint*);
 
     struct CreateInfo {
-        static SkPixelGeometry AdjustGeometry(const SkImageInfo&, TileUsage, SkPixelGeometry);
-
-        // The constructor may change the pixel geometry based on other parameters.
-        CreateInfo(const SkImageInfo& info, TileUsage tileUsage, SkPixelGeometry geo)
+        static SkPixelGeometry AdjustGeometry(const SkImageInfo&, Usage, SkPixelGeometry geo);
+
+        // The construct may change the pixel geometry based on usage as needed.
+        CreateInfo(const SkImageInfo& info, Usage usage, SkPixelGeometry geo)
             : fInfo(info)
-            , fTileUsage(tileUsage)
-            , fPixelGeometry(AdjustGeometry(info, tileUsage, geo))
+            , fUsage(usage)
+            , fPixelGeometry(AdjustGeometry(info, usage, geo))
         {}
 
-        const SkImageInfo       fInfo;
-        const TileUsage         fTileUsage;
-        const SkPixelGeometry   fPixelGeometry;
-    };
-
-#ifdef SK_SUPPORT_LEGACY_ONCREATECOMPATIBLEDEVICE
-    // legacy method name -- please override onCreateDevice instead
+        const SkImageInfo     fInfo;
+        const Usage           fUsage;
+        const SkPixelGeometry fPixelGeometry;
+    };
+
     virtual SkBaseDevice* onCreateCompatibleDevice(const CreateInfo&) {
         return NULL;
     }
-
-    virtual SkBaseDevice* onCreateDevice(const CreateInfo& cinfo, const SkPaint* layerPaint) {
-        return this->onCreateCompatibleDevice(cinfo);
-    }
-#else
-    /**
-     *  Create a new device based on CreateInfo. If the paint is not null, then it represents a
-     *  preview of how the new device will be composed with its creator device (this).
-     */
-    virtual SkBaseDevice* onCreateDevice(const CreateInfo&, const SkPaint*) {
-        return NULL;
-    }
-#endif
 
     virtual void initForRootLayer(SkPixelGeometry geo);