Add SK_API to SkOverdrawCanvas and SkOverdrawColorFilter.

The SkiaRenderer in chromium is going to use the overdraw canvas and
filter for measuring overdraw. Move these headers out of src/ into
include/.

Bug: chromium:704285
Change-Id: I2abb1671b73e3d26552462cf700340a7e3b874f0
Reviewed-on: https://skia-review.googlesource.com/36160
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/gn/core.gni b/gn/core.gni
index efd3eab..65b08db 100644
--- a/gn/core.gni
+++ b/gn/core.gni
@@ -200,7 +200,6 @@
   "$_src/core/SkOrderedReadBuffer.h",
   "$_src/core/SkOSFile.h",
   "$_src/core/SkOverdrawCanvas.cpp",
-  "$_src/core/SkOverdrawCanvas.h",
   "$_src/core/SkPaint.cpp",
   "$_src/core/SkPaintDefaults.h",
   "$_src/core/SkPaintPriv.cpp",
@@ -394,6 +393,7 @@
   "$_include/core/SkMatrix44.h",
   "$_include/core/SkMetaData.h",
   "$_include/core/SkMultiPictureDraw.h",
+  "$_include/core/SkOverdrawCanvas.h",
   "$_include/core/SkPaint.h",
   "$_include/core/SkPath.h",
   "$_include/core/SkPathEffect.h",
diff --git a/gn/effects.gni b/gn/effects.gni
index f3a480d..138b5b5 100644
--- a/gn/effects.gni
+++ b/gn/effects.gni
@@ -46,7 +46,6 @@
   "$_src/effects/SkMorphologyImageFilter.cpp",
   "$_src/effects/SkOffsetImageFilter.cpp",
   "$_src/effects/SkOverdrawColorFilter.cpp",
-  "$_src/effects/SkOverdrawColorFilter.h",
   "$_src/effects/SkPackBits.cpp",
   "$_src/effects/SkPackBits.h",
   "$_src/effects/SkPaintFlagsDrawFilter.cpp",
@@ -106,6 +105,7 @@
   "$_include/effects/SkMagnifierImageFilter.h",
   "$_include/effects/SkMorphologyImageFilter.h",
   "$_include/effects/SkOffsetImageFilter.h",
+  "$_include/effects/SkOverdrawColorFilter.h",
   "$_include/effects/SkPaintFlagsDrawFilter.h",
   "$_include/effects/SkPaintImageFilter.h",
   "$_include/effects/SkPerlinNoiseShader.h",
diff --git a/src/core/SkOverdrawCanvas.h b/include/core/SkOverdrawCanvas.h
similarity index 98%
rename from src/core/SkOverdrawCanvas.h
rename to include/core/SkOverdrawCanvas.h
index 5c247b1..284fe6c 100644
--- a/src/core/SkOverdrawCanvas.h
+++ b/include/core/SkOverdrawCanvas.h
@@ -15,7 +15,7 @@
  *  increments the alpha channel of each pixel every time it would have been touched
  *  by a draw call.  This is useful for detecting overdraw.
  */
-class SkOverdrawCanvas : public SkNWayCanvas {
+class SK_API SkOverdrawCanvas : public SkNWayCanvas {
 public:
     /* Does not take ownership of canvas */
     SkOverdrawCanvas(SkCanvas*);
diff --git a/src/effects/SkOverdrawColorFilter.h b/include/effects/SkOverdrawColorFilter.h
similarity index 95%
rename from src/effects/SkOverdrawColorFilter.h
rename to include/effects/SkOverdrawColorFilter.h
index 0948f70..ac97821 100644
--- a/src/effects/SkOverdrawColorFilter.h
+++ b/include/effects/SkOverdrawColorFilter.h
@@ -19,7 +19,7 @@
  *  5 (or larger) -> fColors[5]
  *
  */
-class SkOverdrawColorFilter : public SkColorFilter {
+class SK_API SkOverdrawColorFilter : public SkColorFilter {
 public:
     static constexpr int kNumColors = 6;
 
diff --git a/src/ports/SkGlobalInitialization_default.cpp b/src/ports/SkGlobalInitialization_default.cpp
index d372f122..52ef365 100644
--- a/src/ports/SkGlobalInitialization_default.cpp
+++ b/src/ports/SkGlobalInitialization_default.cpp
@@ -33,7 +33,7 @@
 #include "SkMergeImageFilter.h"
 #include "SkMorphologyImageFilter.h"
 #include "SkOffsetImageFilter.h"
-#include "../../src/effects/SkOverdrawColorFilter.h"
+#include "SkOverdrawColorFilter.h"
 #include "SkPaintImageFilter.h"
 #include "SkPerlinNoiseShader.h"
 #include "SkPictureImageFilter.h"