Add new API to allow layer hoisting/atlasing across picture piles

src/gpu/gl/SkGLContextHelper.cpp

Index: src/gpu/gl/SkGLContextHelper.cpp
diff --git a/src/gpu/gl/SkGLContextHelper.cpp b/src/gpu/gl/SkGLContextHelper.cpp
index 411e1de01e947bbc667402cfacd51d694ac843ce..22e5fd9367d91289b2b9a2c119c02be182b96492 100644
--- a/src/gpu/gl/SkGLContextHelper.cpp
+++ b/src/gpu/gl/SkGLContextHelper.cpp
@@ -27,6 +27,8 @@ SkGLContextHelper::~SkGLContextHelper() {
     SkSafeUnref(fGL);
 }
 
+extern int gBindFrameBufferCount;
+
 bool SkGLContextHelper::init(GrGLStandard forcedGpuAPI, int width,
                              int height) {
     if (fGL) {
@@ -55,6 +57,7 @@ bool SkGLContextHelper::init(GrGLStandard forcedGpuAPI, int width,
         } while (GR_GL_NO_ERROR != error);
 
         SK_GL(*this, GenFramebuffers(1, &fFBO));
+        gBindFrameBufferCount++;
         SK_GL(*this, BindFramebuffer(GR_GL_FRAMEBUFFER, fFBO));
         SK_GL(*this, GenRenderbuffers(1, &fColorBufferID));
         SK_GL(*this, BindRenderbuffer(GR_GL_RENDERBUFFER, fColorBufferID));