Allow SkiaVkRenderEngine to not be compiled

A device will use RenderEngine with either SkiaVk or SkiaGL, but never
both at the same time.  Given that the choice is controlled by a
build-time value in the device's "device.mk" file, to save space, we
should allow the RenderEngine back-ends to be optionally built.  For
now, we'll only do this for SkiaVkRenderEngine.

Test: Compile
Bug: 259323498
Change-Id: Id547feaee7e8aeb4e46759d3d7c9c5dbe18f5211
diff --git a/libs/renderengine/RenderEngine.cpp b/libs/renderengine/RenderEngine.cpp
index d08c221..341c011 100644
--- a/libs/renderengine/RenderEngine.cpp
+++ b/libs/renderengine/RenderEngine.cpp
@@ -39,8 +39,12 @@
             ALOGD("RenderEngine with SkiaGL Backend");
             return renderengine::skia::SkiaGLRenderEngine::create(args);
         case RenderEngineType::SKIA_VK:
+#ifdef RE_SKIAVK
             ALOGD("RenderEngine with SkiaVK Backend");
             return renderengine::skia::SkiaVkRenderEngine::create(args);
+#else
+            LOG_ALWAYS_FATAL("Requested VK backend, but RE_SKIAVK is not defined!");
+#endif
         case RenderEngineType::SKIA_GL_THREADED: {
             ALOGD("Threaded RenderEngine with SkiaGL Backend");
             return renderengine::threaded::RenderEngineThreaded::create(
@@ -50,12 +54,16 @@
                     args.renderEngineType);
         }
         case RenderEngineType::SKIA_VK_THREADED:
+#ifdef RE_SKIAVK
             ALOGD("Threaded RenderEngine with SkiaVK Backend");
             return renderengine::threaded::RenderEngineThreaded::create(
                     [args]() {
                         return android::renderengine::skia::SkiaVkRenderEngine::create(args);
                     },
                     args.renderEngineType);
+#else
+            LOG_ALWAYS_FATAL("Requested VK backend, but RE_SKIAVK is not defined!");
+#endif
         case RenderEngineType::GLES:
         default:
             ALOGD("RenderEngine with GLES Backend");
diff --git a/libs/renderengine/skia/SkiaVkRenderEngine.cpp b/libs/renderengine/skia/SkiaVkRenderEngine.cpp
index f9424f0..2b8495c 100644
--- a/libs/renderengine/skia/SkiaVkRenderEngine.cpp
+++ b/libs/renderengine/skia/SkiaVkRenderEngine.cpp
@@ -14,6 +14,10 @@
  * limitations under the License.
  */
 
+// Allow the SkiaVkRenderEngine class to not be compiled, to save space
+// NOTE: In order to build this class, define `RE_SKIAVK` in a build file.
+#ifdef RE_SKIAVK
+
 // #define LOG_NDEBUG 0
 #undef LOG_TAG
 #define LOG_TAG "RenderEngine"
@@ -673,3 +677,4 @@
 } // namespace skia
 } // namespace renderengine
 } // namespace android
+#endif // RE_SKIAVK
diff --git a/libs/renderengine/skia/SkiaVkRenderEngine.h b/libs/renderengine/skia/SkiaVkRenderEngine.h
index 2e0cf45..1e42b80 100644
--- a/libs/renderengine/skia/SkiaVkRenderEngine.h
+++ b/libs/renderengine/skia/SkiaVkRenderEngine.h
@@ -17,6 +17,10 @@
 #ifndef SF_SKIAVKRENDERENGINE_H_
 #define SF_SKIAVKRENDERENGINE_H_
 
+// Allow the SkiaVkRenderEngine class to not be compiled, to save space
+// NOTE: In order to build this class, define `RE_SKIAVK` in a build file.
+#ifdef RE_SKIAVK
+
 #include <vk/GrVkBackendContext.h>
 
 #include "SkiaRenderEngine.h"
@@ -55,4 +59,5 @@
 } // namespace renderengine
 } // namespace android
 
-#endif
+#endif // RE_SKIAVK
+#endif // SF_SKIAVKRENDERENGINE_H_
diff --git a/libs/renderengine/tests/RenderEngineTest.cpp b/libs/renderengine/tests/RenderEngineTest.cpp
index f3f2da8..7db95a7 100644
--- a/libs/renderengine/tests/RenderEngineTest.cpp
+++ b/libs/renderengine/tests/RenderEngineTest.cpp
@@ -112,6 +112,7 @@
     virtual bool useColorManagement() const = 0;
 };
 
+#ifdef RE_SKIAVK
 class SkiaVkRenderEngineFactory : public RenderEngineFactory {
 public:
     std::string name() override { return "SkiaVkRenderEngineFactory"; }
@@ -152,6 +153,8 @@
 public:
     bool useColorManagement() const override { return true; }
 };
+#endif // RE_SKIAVK
+
 class SkiaGLESRenderEngineFactory : public RenderEngineFactory {
 public:
     std::string name() override { return "SkiaGLRenderEngineFactory"; }
@@ -1557,11 +1560,17 @@
     expectBufferColor(Rect(kGreyLevels, 1), generator, 2);
 }
 
+#ifdef RE_SKIAVK
 INSTANTIATE_TEST_SUITE_P(PerRenderEngineType, RenderEngineTest,
                          testing::Values(std::make_shared<SkiaGLESRenderEngineFactory>(),
                                          std::make_shared<SkiaGLESCMRenderEngineFactory>(),
                                          std::make_shared<SkiaVkRenderEngineFactory>(),
                                          std::make_shared<SkiaVkCMRenderEngineFactory>()));
+#else  // RE_SKIAVK
+INSTANTIATE_TEST_SUITE_P(PerRenderEngineType, RenderEngineTest,
+                         testing::Values(std::make_shared<SkiaGLESRenderEngineFactory>(),
+                                         std::make_shared<SkiaGLESCMRenderEngineFactory>()));
+#endif // RE_SKIAVK
 
 TEST_P(RenderEngineTest, drawLayers_noLayersToDraw) {
     if (!GetParam()->typeSupported()) {