Update use of SkCanvas and SkDevice to match change in Skia

skia/ext/platform_canvas_mac.cc

Index: skia/ext/platform_canvas_mac.cc
diff --git a/skia/ext/platform_canvas_mac.cc b/skia/ext/platform_canvas_mac.cc
index 33d7eb207574e390ccd415ff97487c51d4f96eec..df3d0ce6df957c974463ee1bfa5dcd6b52ae0d09 100644
--- a/skia/ext/platform_canvas_mac.cc
+++ b/skia/ext/platform_canvas_mac.cc
@@ -9,11 +9,8 @@
 
 namespace skia {
 
-PlatformCanvas::PlatformCanvas() : SkCanvas() {
-}
-
 PlatformCanvas::PlatformCanvas(int width, int height, bool is_opaque)
-    : SkCanvas() {
+    : SkCanvas(SkNEW(SkBitmapPlatformDeviceFactory)) {
   initialize(width, height, is_opaque);
 }
 
@@ -21,7 +18,7 @@ PlatformCanvas::PlatformCanvas(int width,
                                int height,
                                bool is_opaque,
                                CGContextRef context)
-    : SkCanvas() {
+    : SkCanvas(SkNEW(SkBitmapPlatformDeviceFactory)) {
   initialize(width, height, is_opaque);
 }
 
@@ -29,7 +26,7 @@ PlatformCanvas::PlatformCanvas(int width,
                                int height,
                                bool is_opaque,
                                uint8_t* data)
-    : SkCanvas() {
+    : SkCanvas(SkNEW(SkBitmapPlatformDeviceFactory)) {
   initialize(width, height, is_opaque, data);
 }
 
@@ -58,12 +55,4 @@ void PlatformCanvas::endPlatformPaint() {
   // Flushing will be done in onAccessBitmap.
 }
 
-SkDevice* PlatformCanvas::createDevice(SkBitmap::Config config,
-                                       int width,
-                                       int height,
-                                       bool is_opaque, bool isForLayer) {
-  SkASSERT(config == SkBitmap::kARGB_8888_Config);
-  return BitmapPlatformDevice::Create(NULL, width, height, is_opaque);
-}
-
 }  // namespace skia