If requested then cache unprotected buffers even in protected mode

Protected and normal GLContexts belong to the same share_context which
allows them to share textures between them.  As well as allowing us to
add/remove unprotected textures from either context.

Bug: 190567761
Bug: 187870007
Bug: 190628682
Test: librenderengine_test
Change-Id: I1bada6dea04891149f84ca27080d57322c8686da
diff --git a/libs/renderengine/skia/SkiaGLRenderEngine.h b/libs/renderengine/skia/SkiaGLRenderEngine.h
index 97d3b72..758c0f8 100644
--- a/libs/renderengine/skia/SkiaGLRenderEngine.h
+++ b/libs/renderengine/skia/SkiaGLRenderEngine.h
@@ -126,11 +126,9 @@
     // Number of external holders of ExternalTexture references, per GraphicBuffer ID.
     std::unordered_map<GraphicBufferId, int32_t> mGraphicBufferExternalRefs
             GUARDED_BY(mRenderingMutex);
-    // Cache of GL textures that we'll store per GraphicBuffer ID, sliced by GPU context.
+    // Cache of GL textures that we'll store per GraphicBuffer ID, shared between GPU contexts.
     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;
 
     StretchShaderFactory mStretchShaderFactory;