Revert "Add ExternalTexture class into RenderEngine interface"

Revert submission 14086921-renderengine-external-tex

Reason for revert: Potential culprit for b/185361988
Reverted Changes:
I7796764e2:Update WaylandRenderSurface to accomodate interfac...
I13904eec4:Update Readback VTS to align with RenderEngine int...
I222c71e6e:Add ExternalTexture class into RenderEngine interf...

Change-Id: I1501890f4861a3df7ce273f1fe2ccdb275e2632c
diff --git a/services/surfaceflinger/RefreshRateOverlay.cpp b/services/surfaceflinger/RefreshRateOverlay.cpp
index a9fd16c..7a3e433 100644
--- a/services/surfaceflinger/RefreshRateOverlay.cpp
+++ b/services/surfaceflinger/RefreshRateOverlay.cpp
@@ -208,8 +208,7 @@
     return true;
 }
 
-const std::vector<std::shared_ptr<renderengine::ExternalTexture>>&
-RefreshRateOverlay::getOrCreateBuffers(uint32_t fps) {
+const std::vector<sp<GraphicBuffer>>& RefreshRateOverlay::getOrCreateBuffers(uint32_t fps) {
     if (mBufferCache.find(fps) == mBufferCache.end()) {
         // Ensure the range is > 0, so we don't divide by 0.
         const auto rangeLength = std::max(1u, mHighFps - mLowFps);
@@ -223,17 +222,7 @@
         color.g = HIGH_FPS_COLOR.g * fpsScale + LOW_FPS_COLOR.g * (1 - fpsScale);
         color.b = HIGH_FPS_COLOR.b * fpsScale + LOW_FPS_COLOR.b * (1 - fpsScale);
         color.a = ALPHA;
-        auto buffers = SevenSegmentDrawer::drawNumber(fps, color, mShowSpinner);
-        std::vector<std::shared_ptr<renderengine::ExternalTexture>> textures;
-        std::transform(buffers.begin(), buffers.end(), std::back_inserter(textures),
-                       [&](const auto& buffer) -> std::shared_ptr<renderengine::ExternalTexture> {
-                           return std::make_shared<
-                                   renderengine::ExternalTexture>(buffer,
-                                                                  mFlinger.getRenderEngine(),
-                                                                  renderengine::ExternalTexture::
-                                                                          Usage::READABLE);
-                       });
-        mBufferCache.emplace(fps, textures);
+        mBufferCache.emplace(fps, SevenSegmentDrawer::drawNumber(fps, color, mShowSpinner));
     }
 
     return mBufferCache[fps];