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.cpp b/services/surfaceflinger/Layer.cpp
index f181220..1884cfe 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -639,7 +639,7 @@
          * Here we cancel out the orientation component of the WM transform.
          * The scaling and translate components are already included in our bounds
          * computation so it's enough to just omit it in the composition.
-         * See comment in onDraw with ref to b/36727915 for why.
+         * See comment in BufferLayer::prepareClientLayer with ref to b/36727915 for why.
          */
         transform = ui::Transform(invTransform) * tr * bufferOrientation;
     }
@@ -707,12 +707,51 @@
 // drawing...
 // ---------------------------------------------------------------------------
 
-void Layer::draw(const RenderArea& renderArea, const Region& clip) {
-    onDraw(renderArea, clip, false);
+bool Layer::prepareClientLayer(const RenderArea& renderArea, const Region& clip,
+                               Region& clearRegion, renderengine::LayerSettings& layer) {
+    return prepareClientLayer(renderArea, clip, false, clearRegion, layer);
 }
 
-void Layer::draw(const RenderArea& renderArea, bool useIdentityTransform) {
-    onDraw(renderArea, Region(renderArea.getBounds()), useIdentityTransform);
+bool Layer::prepareClientLayer(const RenderArea& renderArea, bool useIdentityTransform,
+                               Region& clearRegion, renderengine::LayerSettings& layer) {
+    return prepareClientLayer(renderArea, Region(renderArea.getBounds()), useIdentityTransform,
+                              clearRegion, layer);
+}
+
+bool Layer::prepareClientLayer(const RenderArea& /*renderArea*/, const Region& /*clip*/,
+                               bool useIdentityTransform, Region& /*clearRegion*/,
+                               renderengine::LayerSettings& layer) {
+    FloatRect bounds = computeBounds();
+    half alpha = getAlpha();
+    layer.geometry.boundaries = bounds;
+    if (useIdentityTransform) {
+        layer.geometry.positionTransform = mat4();
+    } else {
+        const ui::Transform transform = getTransform();
+        mat4 m;
+        m[0][0] = transform[0][0];
+        m[0][1] = transform[0][1];
+        m[0][3] = transform[0][2];
+        m[1][0] = transform[1][0];
+        m[1][1] = transform[1][1];
+        m[1][3] = transform[1][2];
+        m[3][0] = transform[2][0];
+        m[3][1] = transform[2][1];
+        m[3][3] = transform[2][2];
+        layer.geometry.positionTransform = m;
+    }
+
+    if (hasColorTransform()) {
+        layer.colorTransform = getColorTransform();
+    }
+
+    const auto roundedCornerState = getRoundedCornerState();
+    layer.geometry.roundedCornersRadius = roundedCornerState.radius;
+    layer.geometry.roundedCornersCrop = roundedCornerState.cropRect;
+
+    layer.alpha = alpha;
+    layer.sourceDataspace = mCurrentDataSpace;
+    return true;
 }
 
 void Layer::clearWithOpenGL(const RenderArea& renderArea, float red, float green, float blue,