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

tools/bench_pictures_main.cpp

Index: tools/bench_pictures_main.cpp
diff --git a/tools/bench_pictures_main.cpp b/tools/bench_pictures_main.cpp
index ac66dc50d644b1be2a27b6896487def4964bc457..20024e3deca1b99e11a08196665baa62cc0c344a 100644
--- a/tools/bench_pictures_main.cpp
+++ b/tools/bench_pictures_main.cpp
@@ -401,6 +401,8 @@ static int process_input(const char* input,
     return failures;
 }
 
+extern int gBindFrameBufferCount;
+
 int tool_main(int argc, char** argv);
 int tool_main(int argc, char** argv) {
     SetupCrashHandler();
@@ -473,6 +475,7 @@ int tool_main(int argc, char** argv) {
     }
 #endif
     gWriter.end();
+    SkDebugf("\n************** BindFramebuffers: %d**********************\n", gBindFrameBufferCount);
     return 0;
 }