cc: optimize texture allocation.

cc/output/gl_renderer.cc

 // Copyright 2010 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/gl_renderer.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 123 matching lines @@
     case SkXfermode::kColor_Mode:
       return BLEND_MODE_COLOR;
     case SkXfermode::kLuminosity_Mode:
       return BLEND_MODE_LUMINOSITY;
     default:
       NOTREACHED();
       return BLEND_MODE_NONE;
   }
 }
 
+void RoundUpToPow2(gfx::RectF* rect) {
+  float w, h;
+  for (w = 1.f; w < rect->width(); w *= 2.f) {
+  }
+  for (h = 1.f; h < rect->height(); h *= 2.f) {
+  }
+  rect->set_width(w);
+  rect->set_height(h);
+}
+
 // Smallest unit that impact anti-aliasing output. We use this to
 // determine when anti-aliasing is unnecessary.
 const float kAntiAliasingEpsilon = 1.0f / 1024.0f;
 
 // Block or crash if the number of pending sync queries reach this high as
 // something is seriously wrong on the service side if this happens.
 const size_t kMaxPendingSyncQueries = 16;
 
 }  // anonymous namespace
 
@@ skipping 871 matching lines @@
         gfx::Transform transform =
             quad->shared_quad_state->quad_to_target_transform;
         gfx::QuadF clip_quad = gfx::QuadF(gfx::RectF(clip_rect));
         gfx::QuadF local_clip = MapQuadToLocalSpace(transform, clip_quad);
         dst_rect.Intersect(local_clip.BoundingBox());
         // If we've been fully clipped out (by crop rect or clipping), there's
         // nothing to draw.
         if (dst_rect.IsEmpty()) {
           return;
         }
+        // Expand dst_rect size to the nearest power of 2, in order to get
+        // more cache hits in Skia's texture cache.
+        RoundUpToPow2(&dst_rect);
         filter_image = ApplyImageFilter(
             ScopedUseGrContext::Create(this, frame), resource_provider_, rect,
             dst_rect, scale, std::move(filter), contents_texture);
         if (filter_image) {
           filter_image_id = skia::GrBackendObjectToGrGLTextureInfo(
                                 filter_image->getTextureHandle(true))
                                 ->fID;
           DCHECK(filter_image_id);
           rect = dst_rect;
         }
@@ skipping 2603 matching lines @@
       texture_id = pending_overlay_resources_.back()->texture_id();
     }
 
     context_support_->ScheduleOverlayPlane(
         overlay.plane_z_order, overlay.transform, texture_id,
         ToNearestRect(overlay.display_rect), overlay.uv_rect);
   }
 }
 
 }  // namespace cc