Use renderengine::drawLayers api everywhere.

There's some dead code left after this change, which I'll circle around
to removing in the future.

Bug: 118461793
Bug: 123496360
Change-Id: Ic631b0c452f67b353adaa63896e8cd080e391647
Test: librenderengine_test
Test: SurfaceFlinger_test
Test: libsurfaceflinger_unittest
Test: notch hide
Test: screen rotations
Test: photos
Test: adb screencap
Test: adb screenrecord
Test: simulate virtual displays (incl. secure overlays)
Test: go/wm-smoke with gpu composition forced
diff --git a/services/surfaceflinger/Layer.h b/services/surfaceflinger/Layer.h
index d30961a..b9dc8d5 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -413,11 +413,9 @@
     virtual Rect getCrop(const Layer::State& s) const { return s.crop_legacy; }
 
 protected:
-    /*
-     * onDraw - draws the surface.
-     */
-    virtual void onDraw(const RenderArea& renderArea, const Region& clip,
-                        bool useIdentityTransform) = 0;
+    virtual bool prepareClientLayer(const RenderArea& renderArea, const Region& clip,
+                                    bool useIdentityTransform, Region& clearRegion,
+                                    renderengine::LayerSettings& layer) = 0;
 
 public:
     virtual void setDefaultBufferSize(uint32_t /*w*/, uint32_t /*h*/) {}
@@ -466,13 +464,15 @@
     // If a buffer was replaced this frame, release the former buffer
     virtual void releasePendingBuffer(nsecs_t /*dequeueReadyTime*/) { }
 
-
     /*
-     * draw - performs some global clipping optimizations
-     * and calls onDraw().
+     * prepareClientLayer - populates a renderengine::LayerSettings to passed to
+     * RenderEngine::drawLayers. Returns true if the layer can be used, and
+     * false otherwise.
      */
-    void draw(const RenderArea& renderArea, const Region& clip);
-    void draw(const RenderArea& renderArea, bool useIdentityTransform);
+    bool prepareClientLayer(const RenderArea& renderArea, const Region& clip, Region& clearRegion,
+                            renderengine::LayerSettings& layer);
+    bool prepareClientLayer(const RenderArea& renderArea, bool useIdentityTransform,
+                            Region& clearRegion, renderengine::LayerSettings& layer);
 
     /*
      * doTransaction - process the transaction. This is a good place to figure
@@ -803,7 +803,13 @@
     FenceTimeline mReleaseTimeline;
 
     // main thread
+    // Active buffer fields
     sp<GraphicBuffer> mActiveBuffer;
+    sp<Fence> mActiveBufferFence;
+    // False if the buffer and its contents have been previously used for GPU
+    // composition, true otherwise.
+    bool mIsActiveBufferUpdatedForGpu = true;
+
     ui::Dataspace mCurrentDataSpace = ui::Dataspace::UNKNOWN;
     Rect mCurrentCrop;
     uint32_t mCurrentTransform{0};
@@ -857,7 +863,6 @@
                                        const LayerVector::Visitor& visitor);
     LayerVector makeChildrenTraversalList(LayerVector::StateSet stateSet,
                                           const std::vector<Layer*>& layersInTree);
-
     /**
      * Retuns the child bounds in layer space cropped to its bounds as well all its parent bounds.
      * The cropped bounds must be transformed back from parent layer space to child layer space by