Not for review.

cc/output/overlay_renderer.cc

Index: cc/output/overlay_renderer.cc
diff --git a/cc/output/overlay_renderer.cc b/cc/output/overlay_renderer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..be9c8eb36cdecf9f2c78cdc60a760539b328decc
--- /dev/null
+++ b/cc/output/overlay_renderer.cc
@@ -0,0 +1,126 @@
+// Copyright 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "cc/output/overlay_renderer.h"
+
+#include <utility>
+#include <vector>
+
+#include "base/containers/hash_tables.h"
+#include "base/containers/scoped_ptr_hash_map.h"
+#include "base/debug/trace_event.h"
+#include "base/metrics/histogram.h"
+#include "cc/base/math_util.h"
+#include "cc/output/copy_output_request.h"
+#include "cc/quads/draw_quad.h"
+#include "ui/gfx/rect_conversions.h"
+#include "ui/gfx/transform.h"
+#include "ui/gfx/ozone/overlay_hal_ozone.h"
+
+namespace cc {
+
+namespace {
+
+class SingleOverlayOnTop : public OverlayRenderer::Strategy {

[rjkroege, 2014/01/10 19:14:04]

the notion here is that in the fullness of time that there could be a range of
different strategies? The strategy encompasses the "can i overlayz my layerz?"
concept?

+ public:
+   SingleOverlayOnTop(gfx::OverlayHALOzone* hal);
+   virtual bool Attempt(RenderPassList* render_passes_in_draw_order) OVERRIDE;
+ private:
+   gfx::OverlayHALOzone* hal_;
+};
+
+SingleOverlayOnTop::SingleOverlayOnTop(gfx::OverlayHALOzone* hal) : hal_(hal) {}
+
+bool SingleOverlayOnTop::Attempt(RenderPassList* render_passes_in_draw_order) {

[rjkroege, 2014/01/10 19:14:04]

An alternate implementation would have this wending its way off the to the HAL
yes?

+  // Only attempt to handle very simple case for now.
+  if (render_passes_in_draw_order->size() != 1 || !hal_)
+    return false;
+
+  RenderPass* root_render_pass = render_passes_in_draw_order->back();
+  DCHECK(root_render_pass);
+
+  QuadList& quad_list = root_render_pass->quad_list;
+  QuadList::BackToFrontIterator candidate_quad = quad_list.BackToFrontEnd();
+  for (QuadList::BackToFrontIterator it = quad_list.BackToFrontBegin();
+       it != quad_list.BackToFrontEnd();
+       ++it) {
+    const DrawQuad& quad = *(*it);
+    if (//quad.material == DrawQuad::STREAM_VIDEO_CONTENT ||
+        //quad.material == DrawQuad::YUV_VIDEO_CONTENT ||
+        quad.material == DrawQuad::TEXTURE_CONTENT) {
+      // Don't try for multiple surfaces.
+      if (candidate_quad != quad_list.BackToFrontEnd())
+        return false;
+
+      candidate_quad = it;
+      break;
+    }
+  }
+
+  // Found nothing useful.
+  if (candidate_quad == quad_list.BackToFrontEnd())
+    return false;
+
+  gfx::OverlayHALOzone::SurfaceCandidateList candidates;
+  gfx::OverlayHALOzone::SurfaceCandidate candidate;
+  const DrawQuad& quad = *(*candidate_quad);
+  gfx::RectF float_rect(quad.rect);
+  quad.quadTransform().TransformRect(&float_rect);
+  candidate.rect = gfx::ToNearestRect(float_rect);
+  candidate.format = gfx::OverlayHALOzone::RGBA;
+  candidates.push_back(candidate);
+
+  if (quad_list.size() != 1) {
+    gfx::OverlayHALOzone::SurfaceCandidate main_image;
+    main_image.rect = root_render_pass->output_rect;
+    main_image.format = gfx::OverlayHALOzone::RGBA;
+    candidates.push_back(main_image);
+  }
+
+  // Ask for support
+  hal_->CheckOverlaySupport(&candidates);
+
+  // Only one quad in the main pass, just overlay.
+  if (candidates.size() == 1 && candidates[0].overlay_handled) {
+    root_render_pass->handled_by_overlay_hardware = true;
+    root_render_pass->should_render = false;
+  } else if (candidates.size() == 2 && candidates[0].overlay_handled) {
+    // Add a pass for an overlayable quad
+    scoped_ptr<RenderPass> overlay_pass = RenderPass::Create();
+    overlay_pass->handled_by_overlay_hardware = true;
+    overlay_pass->overlay_hardware_rect = candidate.rect;
+    overlay_pass->should_render = false;
+
+    scoped_ptr<DrawQuad> overlay_quad =
+        quad_list.take((candidate_quad + 1).base());
+    quad_list.erase((candidate_quad + 1).base());
+    overlay_pass->quad_list.push_back(overlay_quad.PassAs<DrawQuad>());
+    render_passes_in_draw_order->insert(render_passes_in_draw_order->begin(),
+                                        overlay_pass.PassAs<RenderPass>());
+  }
+  return true;
+}
+
+}
+
+OverlayRenderer::OverlayRenderer() {}
+OverlayRenderer::~OverlayRenderer() {}
+
+void OverlayRenderer::Initialize() {
+  gfx::OverlayHALOzone* hal = gfx::OverlayHALOzone::GetInstance();
+  if (!hal)
+    return;
+
+  strategies_.push_back(scoped_ptr<Strategy>(new SingleOverlayOnTop(hal)));
+}
+
+void OverlayRenderer::ProcessForOverlays(
+    RenderPassList* render_passes_in_draw_order) {
+  for (size_t i = 0; i < strategies_.size(); i ++) {
+    if (strategies_[i]->Attempt(render_passes_in_draw_order))
+      return;
+  }
+}
+
+}  // namespace cc