Dirty rects always contain full tiles with delegated rendering.

cc/layers/tiled_layer_unittest.cc

 // Copyright 2011 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/layers/tiled_layer.h"
 
 #include <limits>
 #include <vector>
 
 #include "cc/debug/overdraw_metrics.h"
@@ skipping 1116 matching lines @@
     layer->fake_layer_updater()->ClearUpdateCount();
     LayerPushPropertiesTo(layer.get(), layer_impl.get());
   }
   layer_tree_host_->CommitComplete();
 
   ResourceManagerClearAllMemory(layer_tree_host_->contents_texture_manager(),
                                 resource_provider_.get());
   layer_tree_host_->SetRootLayer(NULL);
 }
 
+TEST_F(TiledLayerPartialUpdateTest, \

[danakj, 2013/12/02 15:06:52]

no \ needed

+       VerifyUpdateRectIsPreparedFromOriginalDirtyRects) {
+  // Create one 300 x 200 tiled layer with 3 x 2 tiles.
+  gfx::Rect layer_bounds(0, 0, 300, 200);
+  gfx::Rect dirty_rect(75, 75, 50, 50);
+  gfx::Rect expected_paint_rect(0, 0, 200, 200);
+
+  scoped_refptr<FakeTiledLayer> layer = make_scoped_refptr(
+    new FakeTiledLayer(layer_tree_host_->contents_texture_manager()));
+
+  layer->SetBounds(layer_bounds.size());
+  layer->SetPosition(gfx::PointF(0, 0));
+  layer->draw_properties().visible_content_rect = layer_bounds;
+  layer_tree_host_->SetRootLayer(layer);
+  layer_tree_host_->SetViewportSize(gfx::Size(300, 200));
+
+  // Simulate delegating renderer scenario by not allowing partial texture
+  // updates by default.
+  const_cast<RendererCapabilities&>(layer_tree_host_->proxy()->
+            GetRendererCapabilities()).allow_partial_texture_updates = false;
+
+  // Update all tiles in first update.
+  layer->InvalidateContentRect(layer_bounds);
+  layer_tree_host_->UpdateLayers(queue_.get());
+  UpdateTextures();
+
+  // Now update_rect should contain only dirty_rect.
+  layer->InvalidateContentRect(dirty_rect);
+  layer_tree_host_->UpdateLayers(queue_.get());
+  UpdateTextures();
+
+  gfx::Rect paint_rect = layer->fake_layer_updater()->last_update_rect();
+  EXPECT_FLOAT_RECT_EQ(static_cast<gfx::RectF>(dirty_rect),
+                       layer->update_rect());
+  EXPECT_RECT_EQ(expected_paint_rect, paint_rect);
+  EXPECT_FALSE(dirty_rect.Contains(paint_rect));
+
+  ResourceManagerClearAllMemory(layer_tree_host_->contents_texture_manager(),
+                                resource_provider_.get());
+  layer_tree_host_->SetRootLayer(NULL);
+}
+
 TEST_F(TiledLayerTest, TilesPaintedWithoutOcclusion) {
   scoped_refptr<FakeTiledLayer> layer =
       make_scoped_refptr(new FakeTiledLayer(resource_manager_.get()));
   RenderSurfaceLayerList render_surface_layer_list;
 
   layer_tree_host_->root_layer()->AddChild(layer);
 
   // The tile size is 100x100, so this invalidates and then paints two tiles.
   layer->SetBounds(gfx::Size(100, 200));
   CalcDrawProps(&render_surface_layer_list);
@@ skipping 800 matching lines @@
   // Invalidate the entire layer in layer space. When painting, the rect given
   // to webkit should match the layer's bounds.
   layer->SetNeedsDisplayRect(layer_rect);
   layer->Update(queue_.get(), NULL);
 
   EXPECT_RECT_EQ(layer_rect, layer->tracking_layer_painter()->PaintedRect());
 }
 
 }  // namespace
 }  // namespace cc