remove (dumb) canvas::NewRaster, and rename surface::NewRasterPMColor to N32Premul

src/core/SkCanvas.cpp

Index: src/core/SkCanvas.cpp
diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index a6f263f517dd387510638b00d7bba207e93cda4e..8351a52bf7adbad5b88b20da73c7d37a8a5b38d9 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -2529,23 +2529,6 @@ static bool supported_for_raster_canvas(const SkImageInfo& info) {
     return true;
 }
 
-SkCanvas* SkCanvas::NewRaster(const SkImageInfo& info) {
-    if (!supported_for_raster_canvas(info)) {
-        return NULL;
-    }
-
-    SkBitmap bitmap;
-    if (!bitmap.tryAllocPixels(info)) {
-        return NULL;
-    }
-
-    // should this functionality be moved into allocPixels()?
-    if (!bitmap.info().isOpaque()) {
-        bitmap.eraseColor(0);
-    }
-    return SkNEW_ARGS(SkCanvas, (bitmap));
-}
-
 SkCanvas* SkCanvas::NewRasterDirect(const SkImageInfo& info, void* pixels, size_t rowBytes) {
     if (!supported_for_raster_canvas(info)) {
         return NULL;