Updated SkiaGLRenderEngine stretch logic

Removed explicit flag to disable stretching
surfaceflinger layers with the stretch shader in favor
of leveraging a adb setprop to determine the type of
stretch to apply.

Updated some variable names + types as response
to earlier CL feedback

Bug: 184297961
Test: manual
Change-Id: I4f1d7a7b4a33095d920b3149eb474cbe07c87cb0
diff --git a/libs/renderengine/skia/SkiaGLRenderEngine.cpp b/libs/renderengine/skia/SkiaGLRenderEngine.cpp
index f95c6c6..c2cf2a4 100644
--- a/libs/renderengine/skia/SkiaGLRenderEngine.cpp
+++ b/libs/renderengine/skia/SkiaGLRenderEngine.cpp
@@ -564,10 +564,10 @@
     // which gets similar results for most surfaces
     // Determine later on if we need to leverage the stertch shader within
     // surface flinger
-    if (stretchEffect.hasEffect() && /* DISABLES CODE */ (false)) {
+    if (stretchEffect.hasEffect()) {
         const auto targetBuffer = layer->source.buffer.buffer;
-        const auto graphicsBuffer = targetBuffer ? targetBuffer->getBuffer() : nullptr;
-        if (graphicsBuffer && shader) {
+        const auto graphicBuffer = targetBuffer ? targetBuffer->getBuffer() : nullptr;
+        if (graphicBuffer && shader) {
             shader = mStretchShaderFactory.createSkShader(shader, stretchEffect);
         }
     }
diff --git a/libs/renderengine/skia/SkiaGLRenderEngine.h b/libs/renderengine/skia/SkiaGLRenderEngine.h
index d9caf35..bb8625e 100644
--- a/libs/renderengine/skia/SkiaGLRenderEngine.h
+++ b/libs/renderengine/skia/SkiaGLRenderEngine.h
@@ -120,14 +120,15 @@
 
     // Identifier used or various mappings of layers to various
     // textures or shaders
-    using LayerId = uint64_t;
+    using GraphicBufferId = uint64_t;
 
     // Number of external holders of ExternalTexture references, per GraphicBuffer ID.
-    std::unordered_map<LayerId, int32_t> mGraphicBufferExternalRefs GUARDED_BY(mRenderingMutex);
-    // Cache of GL textures that we'll store per GraphicBuffer ID, sliced by GPU context.
-    std::unordered_map<LayerId, std::shared_ptr<AutoBackendTexture::LocalRef>> mTextureCache
+    std::unordered_map<GraphicBufferId, int32_t> mGraphicBufferExternalRefs
             GUARDED_BY(mRenderingMutex);
-    std::unordered_map<LayerId, std::shared_ptr<AutoBackendTexture::LocalRef>>
+    // Cache of GL textures that we'll store per GraphicBuffer ID, sliced by GPU context.
+    std::unordered_map<GraphicBufferId, std::shared_ptr<AutoBackendTexture::LocalRef>> mTextureCache
+            GUARDED_BY(mRenderingMutex);
+    std::unordered_map<GraphicBufferId, std::shared_ptr<AutoBackendTexture::LocalRef>>
             mProtectedTextureCache GUARDED_BY(mRenderingMutex);
     std::unordered_map<LinearEffect, sk_sp<SkRuntimeEffect>, LinearEffectHasher> mRuntimeEffects;