Add underlays and split off common overlay functionality

cc/output/overlay_strategy_single_on_top.cc

Index: cc/output/overlay_strategy_single_on_top.cc
diff --git a/cc/output/overlay_strategy_single_on_top.cc b/cc/output/overlay_strategy_single_on_top.cc
index 71897ed4596cc1f72bc370bba044136649ff0fe3..c9564568e6c787270c319ae954877c5a66d69937 100644
--- a/cc/output/overlay_strategy_single_on_top.cc
+++ b/cc/output/overlay_strategy_single_on_top.cc
@@ -19,8 +19,9 @@ namespace cc {
 OverlayStrategySingleOnTop::OverlayStrategySingleOnTop(
     OverlayCandidateValidator* capability_checker,
     ResourceProvider* resource_provider)
-    : capability_checker_(capability_checker),
-      resource_provider_(resource_provider) {}
+    : OverlayStrategyCommon(resource_provider),
+      capability_checker_(capability_checker) {
+}
 
 bool OverlayStrategySingleOnTop::IsOverlayQuad(const DrawQuad* draw_quad) {
   unsigned int resource_id;
@@ -37,102 +38,6 @@ bool OverlayStrategySingleOnTop::IsOverlayQuad(const DrawQuad* draw_quad) {
   return resource_provider_->AllowOverlay(resource_id);
 }
 
-bool OverlayStrategySingleOnTop::GetTextureQuadInfo(
-    const TextureDrawQuad& quad,
-    OverlayCandidate* quad_info) {
-  gfx::OverlayTransform overlay_transform =
-      OverlayCandidate::GetOverlayTransform(quad.quadTransform(), quad.flipped);
-  if (quad.background_color != SK_ColorTRANSPARENT ||
-      quad.premultiplied_alpha ||
-      overlay_transform == gfx::OVERLAY_TRANSFORM_INVALID)
-    return false;
-  quad_info->resource_id = quad.resource_id;
-  quad_info->transform = overlay_transform;
-  quad_info->uv_rect = BoundingRect(quad.uv_top_left, quad.uv_bottom_right);
-  return true;
-}
-
-bool OverlayStrategySingleOnTop::GetVideoQuadInfo(
-    const StreamVideoDrawQuad& quad,
-    OverlayCandidate* quad_info) {
-  gfx::OverlayTransform overlay_transform =
-      OverlayCandidate::GetOverlayTransform(quad.quadTransform(), false);
-  if (overlay_transform == gfx::OVERLAY_TRANSFORM_INVALID)
-    return false;
-  if (!quad.matrix.IsScaleOrTranslation()) {
-    // We cannot handle anything other than scaling & translation for texture
-    // coordinates yet.
-    return false;
-  }
-  quad_info->resource_id = quad.resource_id;
-  quad_info->transform = overlay_transform;
-
-  gfx::Point3F uv0 = gfx::Point3F(0, 0, 0);
-  gfx::Point3F uv1 = gfx::Point3F(1, 1, 0);
-  quad.matrix.TransformPoint(&uv0);
-  quad.matrix.TransformPoint(&uv1);
-  gfx::Vector3dF delta = uv1 - uv0;
-  if (delta.x() < 0) {
-    quad_info->transform = OverlayCandidate::ModifyTransform(
-        quad_info->transform, gfx::OVERLAY_TRANSFORM_FLIP_HORIZONTAL);
-    float x0 = uv0.x();
-    uv0.set_x(uv1.x());
-    uv1.set_x(x0);
-    delta.set_x(-delta.x());
-  }
-
-  if (delta.y() < 0) {
-    // In this situation, uv0y < uv1y. Since we overlay inverted, a request
-    // to invert the source texture means we can just output the texture
-    // normally and it will be correct.
-    quad_info->uv_rect = gfx::RectF(uv0.x(), uv1.y(), delta.x(), -delta.y());
-  } else {
-    quad_info->transform = OverlayCandidate::ModifyTransform(
-        quad_info->transform, gfx::OVERLAY_TRANSFORM_FLIP_VERTICAL);
-    quad_info->uv_rect = gfx::RectF(uv0.x(), uv0.y(), delta.x(), delta.y());
-  }
-  return true;
-}
-
-bool OverlayStrategySingleOnTop::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)
-    return false;
-
-  if (draw_quad.material == DrawQuad::TEXTURE_CONTENT) {
-    const TextureDrawQuad& quad = *TextureDrawQuad::MaterialCast(&draw_quad);
-    if (!GetTextureQuadInfo(quad, quad_info))
-      return false;
-  } else if (draw_quad.material == DrawQuad::STREAM_VIDEO_CONTENT) {
-    const StreamVideoDrawQuad& quad =
-        *StreamVideoDrawQuad::MaterialCast(&draw_quad);
-    if (!GetVideoQuadInfo(quad, quad_info))
-      return false;
-  }
-
-  quad_info->format = RGBA_8888;
-  quad_info->display_rect = OverlayCandidate::GetOverlayRect(
-      draw_quad.quadTransform(), draw_quad.rect);
-  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) {