Add underlays and split off common overlay functionality

cc/output/overlay_strategy_common.cc

Index: cc/output/overlay_strategy_common.cc
diff --git a/cc/output/overlay_strategy_single_on_top.cc b/cc/output/overlay_strategy_common.cc
similarity index 52%
copy from cc/output/overlay_strategy_single_on_top.cc
copy to cc/output/overlay_strategy_common.cc
index 71897ed4596cc1f72bc370bba044136649ff0fe3..606e8a514102483a1110b705a69a26f890fe9a2b 100644
--- a/cc/output/overlay_strategy_single_on_top.cc
+++ b/cc/output/overlay_strategy_common.cc
@@ -1,12 +1,11 @@
-// Copyright 2014 The Chromium Authors. All rights reserved.
+// Copyright 2015 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_strategy_single_on_top.h"
+#include "cc/output/overlay_strategy_common.h"
 
 #include <limits>
 
-#include "cc/quads/draw_quad.h"
 #include "cc/quads/solid_color_draw_quad.h"
 #include "cc/quads/stream_video_draw_quad.h"
 #include "cc/quads/texture_draw_quad.h"
@@ -16,30 +15,29 @@
 
 namespace cc {
 
-OverlayStrategySingleOnTop::OverlayStrategySingleOnTop(
-    OverlayCandidateValidator* capability_checker,
+OverlayStrategyCommon::OverlayStrategyCommon(
     ResourceProvider* resource_provider)
-    : capability_checker_(capability_checker),
-      resource_provider_(resource_provider) {}
+    : resource_provider_(resource_provider) {
+}
+OverlayStrategyCommon::~OverlayStrategyCommon() {
+}
 
-bool OverlayStrategySingleOnTop::IsOverlayQuad(const DrawQuad* draw_quad) {
-  unsigned int resource_id;
-  switch (draw_quad->material) {
-    case DrawQuad::TEXTURE_CONTENT:
-      resource_id = TextureDrawQuad::MaterialCast(draw_quad)->resource_id;
-      break;
-    case DrawQuad::STREAM_VIDEO_CONTENT:
-      resource_id = StreamVideoDrawQuad::MaterialCast(draw_quad)->resource_id;
-      break;
-    default:
-      return false;
+bool OverlayStrategyCommon::IsInvisibleQuad(const DrawQuad* draw_quad) {
+  if (draw_quad->material == DrawQuad::SOLID_COLOR) {
+    const SolidColorDrawQuad* solid_quad =
+        SolidColorDrawQuad::MaterialCast(draw_quad);
+    SkColor color = solid_quad->color;
+    float opacity = solid_quad->opacity();
+    float alpha = (SkColorGetA(color) * (1.0f / 255.0f)) * opacity;
+    // Ignore transparent solid color quads.
+    return solid_quad->ShouldDrawWithBlending() &&
+           alpha < std::numeric_limits<float>::epsilon();
   }
-  return resource_provider_->AllowOverlay(resource_id);
+  return false;
 }
 
-bool OverlayStrategySingleOnTop::GetTextureQuadInfo(
-    const TextureDrawQuad& quad,
-    OverlayCandidate* quad_info) {
+bool OverlayStrategyCommon::GetTextureQuadInfo(const TextureDrawQuad& quad,
+                                               OverlayCandidate* quad_info) {
   gfx::OverlayTransform overlay_transform =
       OverlayCandidate::GetOverlayTransform(quad.quadTransform(), quad.flipped);
   if (quad.background_color != SK_ColorTRANSPARENT ||
@@ -52,9 +50,8 @@ bool OverlayStrategySingleOnTop::GetTextureQuadInfo(
   return true;
 }
 
-bool OverlayStrategySingleOnTop::GetVideoQuadInfo(
-    const StreamVideoDrawQuad& quad,
-    OverlayCandidate* quad_info) {
+bool OverlayStrategyCommon::GetVideoQuadInfo(const StreamVideoDrawQuad& quad,
+                                             OverlayCandidate* quad_info) {
   gfx::OverlayTransform overlay_transform =
       OverlayCandidate::GetOverlayTransform(quad.quadTransform(), false);
   if (overlay_transform == gfx::OVERLAY_TRANSFORM_INVALID)
@@ -94,9 +91,8 @@ bool OverlayStrategySingleOnTop::GetVideoQuadInfo(
   return true;
 }
 
-bool OverlayStrategySingleOnTop::GetCandidateQuadInfo(
-    const DrawQuad& draw_quad,
-    OverlayCandidate* quad_info) {
+bool OverlayStrategyCommon::GetCandidateQuadInfo(const DrawQuad& draw_quad,
+                                                 OverlayCandidate* quad_info) {
   // All quad checks.
   if (draw_quad.needs_blending || draw_quad.shared_quad_state->opacity != 1.f ||
       draw_quad.shared_quad_state->blend_mode != SkXfermode::kSrcOver_Mode)
@@ -119,78 +115,4 @@ bool OverlayStrategySingleOnTop::GetCandidateQuadInfo(
   return true;
 }
 
-bool OverlayStrategySingleOnTop::IsInvisibleQuad(const DrawQuad* draw_quad) {
-  if (draw_quad->material == DrawQuad::SOLID_COLOR) {
-    const SolidColorDrawQuad* solid_quad =
-        SolidColorDrawQuad::MaterialCast(draw_quad);
-    SkColor color = solid_quad->color;
-    float opacity = solid_quad->opacity();
-    float alpha = (SkColorGetA(color) * (1.0f / 255.0f)) * opacity;
-    // Ignore transparent solid color quads.
-    return solid_quad->ShouldDrawWithBlending() &&
-           alpha < std::numeric_limits<float>::epsilon();
-  }
-  return false;
-}
-
-bool OverlayStrategySingleOnTop::Attempt(
-    RenderPassList* render_passes_in_draw_order,
-    OverlayCandidateList* candidate_list) {
-  // Only attempt to handle very simple case for now.
-  if (!capability_checker_)
-    return false;
-
-  RenderPass* root_render_pass = render_passes_in_draw_order->back();
-  DCHECK(root_render_pass);
-
-  OverlayCandidate candidate;
-  QuadList& quad_list = root_render_pass->quad_list;
-  auto candidate_iterator = quad_list.end();
-  for (auto it = quad_list.begin(); it != quad_list.end(); ++it) {
-    const DrawQuad* draw_quad = *it;
-    if (IsOverlayQuad(draw_quad)) {
-      // Check that no prior quads overlap it.
-      bool intersects = false;
-      gfx::RectF rect = draw_quad->rect;
-      draw_quad->quadTransform().TransformRect(&rect);
-      for (auto overlap_iter = quad_list.cbegin(); overlap_iter != it;
-           ++overlap_iter) {
-        gfx::RectF overlap_rect = overlap_iter->rect;
-        overlap_iter->quadTransform().TransformRect(&overlap_rect);
-        if (rect.Intersects(overlap_rect) && !IsInvisibleQuad(*overlap_iter)) {
-          intersects = true;
-          break;
-        }
-      }
-      if (intersects || !GetCandidateQuadInfo(*draw_quad, &candidate))
-        continue;
-      candidate_iterator = it;
-      break;
-    }
-  }
-  if (candidate_iterator == quad_list.end())
-    return false;
-
-  // Add our primary surface.
-  OverlayCandidateList candidates;
-  OverlayCandidate main_image;
-  main_image.display_rect = root_render_pass->output_rect;
-  candidates.push_back(main_image);
-
-  // Add the overlay.
-  candidate.plane_z_order = 1;
-  candidates.push_back(candidate);
-
-  // Check for support.
-  capability_checker_->CheckOverlaySupport(&candidates);
-
-  // If the candidate can be handled by an overlay, create a pass for it.
-  if (candidates[1].overlay_handled) {
-    quad_list.EraseAndInvalidateAllPointers(candidate_iterator);
-    candidate_list->swap(candidates);
-    return true;
-  }
-  return false;
-}
-
 }  // namespace cc