SF: Allow SurfaceFlinger creation to be altered

As a first step, we need to be able to build a version of the
/system/binsurfacefligner binary that can (eventually) invoke the
SurfaceFlinger constructor to pass a "factory" class to replace certain
key types.

The unittest will also be able to use it to construct mocks by default.

Bug: None
Test: marlin builds, cheets_x86_64 builds (and overrides default)

Change-Id: Id6d5cabf0dd54e85ac0e6706edf3cbe8a0288bc3
diff --git a/services/surfaceflinger/Android.bp b/services/surfaceflinger/Android.bp
index 744bdba..4f12d3e 100644
--- a/services/surfaceflinger/Android.bp
+++ b/services/surfaceflinger/Android.bp
@@ -4,6 +4,7 @@
         "-DLOG_TAG=\"SurfaceFlinger\"",
         "-Wall",
         "-Werror",
+        "-Wformat",
         "-Wthread-safety",
         "-Wunused",
         "-Wunreachable-code",
@@ -18,6 +19,10 @@
         "-DGL_GLEXT_PROTOTYPES",
         "-DEGL_EGLEXT_PROTOTYPES",
     ],
+    include_dirs: [
+        "frameworks/native/vulkan/vkjson",
+        "frameworks/native/vulkan/include",
+    ],
     shared_libs: [
         "android.frameworks.vr.composer@1.0",
         "android.hardware.configstore-utils",
@@ -84,6 +89,18 @@
     ],
 }
 
+cc_defaults {
+    name: "libsurfaceflinger_production_defaults",
+    defaults: ["libsurfaceflinger_defaults"],
+    cflags: [
+        "-fvisibility=hidden",
+        "-fwhole-program-vtables", // requires ThinLTO
+    ],
+    lto: {
+        thin: true,
+    },
+}
+
 cc_library_headers {
     name: "libsurfaceflinger_headers",
     export_include_dirs: ["."],
@@ -137,33 +154,23 @@
 }
 
 cc_library_shared {
+    // Please use libsurfaceflinger_defaults to configure how the sources are
+    // built, so the same settings can be used elsewhere.
     name: "libsurfaceflinger",
-    defaults: ["libsurfaceflinger_defaults"],
-    cflags: [
-        "-fvisibility=hidden",
-        "-Werror=format",
-    ],
+    defaults: ["libsurfaceflinger_production_defaults"],
     srcs: [
         ":libsurfaceflinger_sources",
+
+        // Note: SurfaceFlingerFactory is not in the default sources so that it
+        // can be easily replaced.
+        "SurfaceFlingerFactory.cpp",
     ],
     logtags: ["EventLog/EventLogTags.logtags"],
-    include_dirs: [
-        "frameworks/native/vulkan/vkjson",
-        "frameworks/native/vulkan/include",
-    ],
-    cppflags: [
-        "-fwhole-program-vtables", // requires ThinLTO
-    ],
-    lto: {
-        thin: true,
-    },
 }
 
-cc_binary {
-    name: "surfaceflinger",
+cc_defaults {
+    name: "libsurfaceflinger_binary",
     defaults: ["surfaceflinger_defaults"],
-    init_rc: ["surfaceflinger.rc"],
-    srcs: ["main_surfaceflinger.cpp"],
     whole_static_libs: [
         "libsigchain",
     ],
@@ -180,7 +187,6 @@
         "libhidltransport",
         "liblayers_proto",
         "liblog",
-        "libsurfaceflinger",
         "libtimestats_proto",
         "libutils",
     ],
@@ -189,19 +195,19 @@
         "libtrace_proto",
     ],
     ldflags: ["-Wl,--export-dynamic"],
+}
 
-    // TODO(b/71715793): These version-scripts are required due to the use of
-    // whole_static_libs to pull in libsigchain. To work, the files had to be
-    // locally duplicated from their original location
-    // $ANDROID_ROOT/art/sigchainlib/
-    multilib: {
-        lib32: {
-            version_script: "version-script32.txt",
-        },
-        lib64: {
-            version_script: "version-script64.txt",
-        },
-    },
+filegroup {
+    name: "surfaceflinger_binary_sources",
+    srcs: ["main_surfaceflinger.cpp"],
+}
+
+cc_binary {
+    name: "surfaceflinger",
+    defaults: ["libsurfaceflinger_binary"],
+    init_rc: ["surfaceflinger.rc"],
+    srcs: [":surfaceflinger_binary_sources"],
+    shared_libs: ["libsurfaceflinger"],
 }
 
 cc_library_shared {