Move ccpr headers for display list out of include/private.

This partially undoes 774168efac172d096cd7f09841bce51650cb6e84 "Allow
CCPR in DDL mode (take 2)". The issue appears to have been the use of a
not fully defined type (destructor could not be instantiated) because
the private fields were also dllexported, requiring the destructors to
exist in all translation units which included the header. Only the parts
of the class which are actually public are now marked as exported.

Change-Id: I8a79bd5d8962e94c24f7563d496744bb278153fa
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/214020
Commit-Queue: Ben Wagner <bungeman@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
diff --git a/src/gpu/GrRenderTargetOpList.h b/src/gpu/GrRenderTargetOpList.h
index e27f694..2eec472 100644
--- a/src/gpu/GrRenderTargetOpList.h
+++ b/src/gpu/GrRenderTargetOpList.h
@@ -12,8 +12,8 @@
 #include "include/core/SkStrokeRec.h"
 #include "include/core/SkTypes.h"
 #include "include/private/GrOpList.h"
-#include "include/private/SkArenaAlloc.h"
 #include "include/private/SkTArray.h"
+#include "src/core/SkArenaAlloc.h"
 #include "src/core/SkClipStack.h"
 #include "src/core/SkStringUtils.h"
 #include "src/core/SkTLazy.h"