Add SK_API to base classes of classes with SK_API.
https://codereview.appspot.com/6683044/

This change should unblock rolling Skia DEPS past r5914.
TBR=reed


git-svn-id: http://skia.googlecode.com/svn/trunk@5946 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/core/SkDrawFilter.h b/include/core/SkDrawFilter.h
index 73b2ca5..7471f9b 100644
--- a/include/core/SkDrawFilter.h
+++ b/include/core/SkDrawFilter.h
@@ -21,7 +21,7 @@
  *  used for the actual drawing. Note: this modification only lasts for the
  *  current draw, as a temporary copy of the paint is used.
  */
-class SkDrawFilter : public SkRefCnt {
+class SK_API SkDrawFilter : public SkRefCnt {
 public:
     SK_DECLARE_INST_COUNT(SkDrawFilter)
 
diff --git a/include/core/SkMaskFilter.h b/include/core/SkMaskFilter.h
index 6652f40..47cf516 100644
--- a/include/core/SkMaskFilter.h
+++ b/include/core/SkMaskFilter.h
@@ -31,7 +31,7 @@
 
     Blur and emboss are implemented as subclasses of SkMaskFilter.
 */
-class SkMaskFilter : public SkFlattenable {
+class SK_API SkMaskFilter : public SkFlattenable {
 public:
     SK_DECLARE_INST_COUNT(SkMaskFilter)
 
diff --git a/include/core/SkRasterizer.h b/include/core/SkRasterizer.h
index 0791713..5f71d3f 100644
--- a/include/core/SkRasterizer.h
+++ b/include/core/SkRasterizer.h
@@ -18,7 +18,7 @@
 class SkPath;
 struct SkIRect;
 
-class SkRasterizer : public SkFlattenable {
+class SK_API SkRasterizer : public SkFlattenable {
 public:
     SK_DECLARE_INST_COUNT(SkRasterizer)