Add code needed to build skia as a windows dll within the chromium project.
- Export/import skia APIs if SKIA_DLL is defined.
- This change has no effect on skia.

Review URL: http://codereview.appspot.com/4282042

git-svn-id: http://skia.googlecode.com/svn/trunk@944 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/core/SkCanvas.h b/include/core/SkCanvas.h
index 5aecacb..0a1b393 100644
--- a/include/core/SkCanvas.h
+++ b/include/core/SkCanvas.h
@@ -51,7 +51,7 @@
     color, typeface, textSize, strokeWidth, shader (e.g. gradients, patterns),
     etc.
 */
-class SkCanvas : public SkRefCnt {
+class SK_API SkCanvas : public SkRefCnt {
 public:
     /** Construct a canvas with the given device factory.
         @param factory  Specify the factory for generating additional devices.
@@ -758,7 +758,7 @@
         call made on the canvas. Ownership of all pointers in the iterator stays
         with the canvas, so none of them should be modified or deleted.
     */
-    class LayerIter /*: SkNoncopyable*/ {
+    class SK_API LayerIter /*: SkNoncopyable*/ {
     public:
         /** Initialize iterator with canvas, and set values for 1st device */
         LayerIter(SkCanvas*, bool skipEmptyClips);