SkPictureAnalyzer: expose the number of slow GPU commands.

include/core/SkPictureAnalyzer.h

Index: include/core/SkPictureAnalyzer.h
diff --git a/include/core/SkPictureAnalyzer.h b/include/core/SkPictureAnalyzer.h
index b58807ca89361845be31b886362f19f42ade29dc..c46ca1e85436999cd2c89138f42640878c3e56d2 100644
--- a/include/core/SkPictureAnalyzer.h
+++ b/include/core/SkPictureAnalyzer.h
@@ -48,6 +48,12 @@ public:
      */
     bool suitableForGpuRasterization(const char** whyNot = nullptr) const;
 
+    /**
+     * Returns the number of commands which are slow to draw on the GPU, capped at the predicate
+     * max.
+     */
+    uint32_t numSlowGpuCommands() { return fNumSlowPaths; }
+
 private:
     uint32_t fNumSlowPaths;