Refactor OverlayStrategySandwich and OverlayStrategyCommon

cc/output/overlay_candidate.cc

 // Copyright 2014 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_candidate.h"
 
 #include <algorithm>
 #include <limits>
 #include "base/logging.h"
 #include "cc/base/math_util.h"
@@ skipping 193 matching lines @@
       return FromIOSurfaceQuad(IOSurfaceDrawQuad::MaterialCast(quad),
                                candidate);
     default:
       break;
   }
 
   return false;
 }
 
 // static
+bool OverlayCandidate::IsInvisibleQuad(const DrawQuad* quad) {
+  if (quad->material == DrawQuad::SOLID_COLOR) {
+    SkColor color = SolidColorDrawQuad::MaterialCast(quad)->color;
+    float opacity = quad->shared_quad_state->opacity;
+    float alpha = (SkColorGetA(color) * (1.0f / 255.0f)) * opacity;
+    return quad->ShouldDrawWithBlending() &&
+           alpha < std::numeric_limits<float>::epsilon();
+  }
+  return false;
+}
+
+// static
 bool OverlayCandidate::FromTextureQuad(const TextureDrawQuad* quad,
                                        OverlayCandidate* candidate) {
   if (!quad->allow_overlay())
     return false;
   gfx::OverlayTransform overlay_transform = GetOverlayTransform(
       quad->shared_quad_state->quad_to_target_transform, quad->y_flipped);
   if (quad->background_color != SK_ColorTRANSPARENT ||
       quad->premultiplied_alpha ||
       overlay_transform == gfx::OVERLAY_TRANSFORM_INVALID)
     return false;
@@ skipping 59 matching lines @@
   if (overlay_transform != gfx::OVERLAY_TRANSFORM_NONE)
     return false;
   candidate->resource_id = quad->io_surface_resource_id();
   candidate->resource_size_in_pixels = quad->io_surface_size;
   candidate->transform = overlay_transform;
   candidate->uv_rect = gfx::RectF(1.f, 1.f);
   return true;
 }
 
 }  // namespace cc