Ensure that SkDeferredCanvas::onCreateCompatibleDevice unrefs its temp device.

Also update my GM to use createCompatibleDevice.

Review URL: https://codereview.appspot.com/6357061

git-svn-id: http://skia.googlecode.com/svn/trunk@4450 2bbb7eff-a529-9590-31e7-b0007b416f81

gm/extractbitmap.cpp

@@ -72,13 +72,11 @@ protected:
             canvas->translate(0, SkIntToScalar(bitmap.height() + 20));
             canvas->drawBitmap(subset, 0, 0);
         }
-/*
+
         // Now do the same but with a device bitmap as source image
-        SkRefPtr<SkDevice> primaryDevice(canvas->getDevice());
-        SkRefPtr<SkDevice> secondDevice(canvas->createCompatibleDevice(
+        SkAutoTUnref<SkDevice> secondDevice(canvas->createCompatibleDevice(
             SkBitmap::kARGB_8888_Config, bitmap.width(), 
             bitmap.height(), true));
-        secondDevice->unref();
         SkCanvas secondCanvas(secondDevice.get());
         secondCanvas.writePixels(bitmap, 0, 0);
 
@@ -91,7 +89,7 @@ protected:
 
         canvas->drawBitmap(deviceBitmap, 0, 0);
         canvas->drawBitmap(deviceSubset, 0, 0);
-*/
+
     }
     
 private:

src/utils/SkDeferredCanvas.cpp

@@ -589,9 +589,9 @@ SkDevice* SkDeferredCanvas::DeferredDevice::onCreateCompatibleDevice(
     // Save layer usage not supported, and not required by SkDeferredCanvas.
     SkASSERT(usage != kSaveLayer_Usage);
     // Create a compatible non-deferred device.
-    SkDevice* compatibleDevice = 
-        fImmediateDevice->createCompatibleDevice(config, width, height, 
-            isOpaque);
+    SkAutoTUnref<SkDevice> compatibleDevice
+        (fImmediateDevice->createCompatibleDevice(config, width, height,
+            isOpaque));
     return SkNEW_ARGS(DeferredDevice, (compatibleDevice, fDeviceContext));
 }