Add support for background blurs

Bug: 141640413
Fixes: 146384234
Test: adb shell setprop debug.sf.disableBlurs 1
Test: adb shell setprop debug.sf.gaussianBlur 0
Test: adb shell setprop ro.surface_flinger.supports_background_blur 1
Test: ./SurfaceFlinger_test --gtest_filter=Layer*Tests/Layer*Test.SetBackgroundBlur*
Test: ./librenderengine_test --gtest_filter=*BlurBackground*"
Test: atest SurfaceFlinger_test:SurfaceInterceptorTest#InterceptBackgroundBlurRadiusUpdateWorks
Change-Id: I5194c910fe7062f33e70943867012539e6c6626a
diff --git a/services/surfaceflinger/SurfaceInterceptor.h b/services/surfaceflinger/SurfaceInterceptor.h
index c6f9e8a..a665f62 100644
--- a/services/surfaceflinger/SurfaceInterceptor.h
+++ b/services/surfaceflinger/SurfaceInterceptor.h
@@ -152,6 +152,8 @@
     void addLayerStackLocked(Transaction* transaction, int32_t layerId, uint32_t layerStack);
     void addCropLocked(Transaction* transaction, int32_t layerId, const Rect& rect);
     void addCornerRadiusLocked(Transaction* transaction, int32_t layerId, float cornerRadius);
+    void addBackgroundBlurRadiusLocked(Transaction* transaction, int32_t layerId,
+                                       int32_t backgroundBlurRadius);
     void addDeferTransactionLocked(Transaction* transaction, int32_t layerId,
             const sp<const Layer>& layer, uint64_t frameNumber);
     void addOverrideScalingModeLocked(Transaction* transaction, int32_t layerId,