cc: Ensure that skewport.Contains(visible_rect) is always true.

cc/tiles/picture_layer_tiling_unittest.cc

 // Copyright 2012 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 <limits>
 #include <set>
 
 #include "cc/base/math_util.h"
 #include "cc/test/fake_output_surface.h"
 #include "cc/test/fake_output_surface_client.h"
@@ skipping 611 matching lines @@
   // Move the skewport really far in one direction.
   gfx::Rect move_skewport_far =
       tiling->ComputeSkewport(1.5, gfx::Rect(0, 5000, 100, 100));
   EXPECT_EQ(0, move_skewport_far.x());
   EXPECT_EQ(5000, move_skewport_far.y());
   EXPECT_EQ(100, move_skewport_far.width());
   EXPECT_EQ(175, move_skewport_far.height());
   EXPECT_TRUE(move_skewport_far.Contains(gfx::Rect(0, 5000, 100, 100)));
 }
 
+TEST(PictureLayerTilingTest, ComputeSkewportExtremeCases) {
+  FakePictureLayerTilingClient client;
+
+  gfx::Size layer_bounds(200, 200);
+  client.SetTileSize(gfx::Size(100, 100));
+  LayerTreeSettings settings;
+  scoped_refptr<FakePicturePileImpl> pile =
+      FakePicturePileImpl::CreateFilledPileWithDefaultTileSize(layer_bounds);
+  scoped_ptr<TestablePictureLayerTiling> tiling =
+      TestablePictureLayerTiling::Create(ACTIVE_TREE, 1.0f, pile, &client,
+                                         settings);
+
+  gfx::Rect viewport1(-1918, 255860, 4010, 2356);
+  gfx::Rect viewport2(-7088, -91738, 14212, 8350);
+  gfx::Rect viewport3(-12730024, -158883296, 24607540, 14454512);
+  double time = 1.0;
+  tiling->ComputeTilePriorityRects(viewport1, 1.f, time, Occlusion());
+  time += 0.016;
+  EXPECT_TRUE(tiling->ComputeSkewport(time, viewport2).Contains(viewport2));
+  tiling->ComputeTilePriorityRects(viewport2, 1.f, time, Occlusion());
+  time += 0.016;
+  EXPECT_TRUE(tiling->ComputeSkewport(time, viewport3).Contains(viewport3));
+}
+
 TEST(PictureLayerTilingTest, ComputeSkewport) {
   FakePictureLayerTilingClient client;
 
   gfx::Rect viewport(0, 0, 100, 100);
   gfx::Size layer_bounds(200, 200);
 
   client.SetTileSize(gfx::Size(100, 100));
 
   scoped_refptr<FakePicturePileImpl> pile =
       FakePicturePileImpl::CreateFilledPileWithDefaultTileSize(layer_bounds);
@@ skipping 1324 matching lines @@
   tiling_->SetRasterSourceAndResize(pile);
 
   // Tile size in the tiling should be resized to 250x200.
   EXPECT_EQ(250, tiling_->TilingDataForTesting().max_texture_size().width());
   EXPECT_EQ(200, tiling_->TilingDataForTesting().max_texture_size().height());
   EXPECT_EQ(0u, tiling_->AllTilesForTesting().size());
 }
 
 }  // namespace
 }  // namespace cc