Update from https://crrev.com/316786

cc/resources/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 "cc/resources/picture_layer_tiling.h"
 
 #include <limits>
 #include <set>
 
 #include "cc/base/math_util.h"
@@ skipping 673 matching lines @@
   scoped_refptr<FakePicturePileImpl> pile =
       FakePicturePileImpl::CreateFilledPileWithDefaultTileSize(layer_bounds);
   scoped_ptr<TestablePictureLayerTiling> tiling =
       TestablePictureLayerTiling::Create(0.25f, pile, &client, settings);
   gfx::Rect viewport_in_content_space =
       gfx::ToEnclosedRect(gfx::ScaleRect(viewport, 0.25f));
 
   tiling->ComputeTilePriorityRects(viewport, 1.f, 1.0, Occlusion());
   tiling->UpdateAllTilePrioritiesForTesting();
 
-  gfx::Rect soon_rect = viewport;
-  soon_rect.Inset(-312.f, -312.f, -312.f, -312.f);
-  gfx::Rect soon_rect_in_content_space =
-      gfx::ToEnclosedRect(gfx::ScaleRect(soon_rect, 0.25f));
+  // Compute the soon border.
+  float inset = PictureLayerTiling::CalculateSoonBorderDistance(
+      viewport_in_content_space, 1.0f / 0.25f);
+  gfx::Rect soon_rect_in_content_space = viewport_in_content_space;
+  soon_rect_in_content_space.Inset(-inset, -inset);
 
   // Sanity checks.
   for (int i = 0; i < 47; ++i) {
     for (int j = 0; j < 47; ++j) {
       EXPECT_TRUE(tiling->TileAt(i, j)) << "i: " << i << " j: " << j;
     }
   }
   for (int i = 0; i < 47; ++i) {
     EXPECT_FALSE(tiling->TileAt(i, 47)) << "i: " << i;
     EXPECT_FALSE(tiling->TileAt(47, i)) << "i: " << i;
@@ skipping 48 matching lines @@
 
   priority = tiling->TileAt(3, 4)->priority(ACTIVE_TREE);
   EXPECT_FLOAT_EQ(40.f, priority.distance_to_visible);
 
   // Move the viewport down 40 pixels.
   viewport = gfx::Rect(0, 40, 100, 100);
   viewport_in_content_space =
       gfx::ToEnclosedRect(gfx::ScaleRect(viewport, 0.25f));
   gfx::Rect skewport = tiling->ComputeSkewport(2.0, viewport_in_content_space);
 
-  soon_rect = viewport;
-  soon_rect.Inset(-312.f, -312.f, -312.f, -312.f);
-  soon_rect_in_content_space =
-      gfx::ToEnclosedRect(gfx::ScaleRect(soon_rect, 0.25f));
+  // Compute the soon border.
+  inset = PictureLayerTiling::CalculateSoonBorderDistance(
+      viewport_in_content_space, 1.0f / 0.25f);
+  soon_rect_in_content_space = viewport_in_content_space;
+  soon_rect_in_content_space.Inset(-inset, -inset);
 
   EXPECT_EQ(0, skewport.x());
   EXPECT_EQ(10, skewport.y());
   EXPECT_EQ(25, skewport.width());
   EXPECT_EQ(35, skewport.height());
 
   tiling->ComputeTilePriorityRects(viewport, 1.f, 2.0, Occlusion());
   tiling->UpdateAllTilePrioritiesForTesting();
 
   have_now = false;
@@ skipping 1108 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_->AllRefTilesForTesting().size());
 }
 
 }  // namespace
 }  // namespace cc