Dirty rects always contain full tiles with delegated rendering.

cc/layers/tiled_layer_unittest.cc

Index: cc/layers/tiled_layer_unittest.cc
diff --git a/cc/layers/tiled_layer_unittest.cc b/cc/layers/tiled_layer_unittest.cc
index 42ef29cc93ed27959bb30d510a279d9cb90fe9b9..0a50968ef99ec5609d3a6ea9de90317dfef41170 100644
--- a/cc/layers/tiled_layer_unittest.cc
+++ b/cc/layers/tiled_layer_unittest.cc
@@ -1134,6 +1134,48 @@ TEST_F(TiledLayerPartialUpdateTest, PartialUpdates) {
   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()));