cc: Ensure that layer bounds * content scale doesn't overflow

cc/layers/picture_layer_impl_unittest.cc

 // Copyright 2013 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/picture_layer_impl.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <limits>
@@ skipping 692 matching lines @@
   ResetTilingsAndRasterScales();
   EXPECT_EQ(0u, active_layer()->tilings()->num_tilings());
   SetContentsScaleOnBothLayers(32.0f, 1.0f, 32.0f, 1.0f, 0.f, false);
   EXPECT_EQ(32.f, active_layer()->HighResTiling()->contents_scale());
   host_impl()->PinchGestureBegin();
   SetContentsScaleOnBothLayers(1.0f, 1.0f, 1.0f, 1.0f, 0.f, false);
   SetContentsScaleOnBothLayers(1.0f, 1.0f, 1.0f, 1.0f, 0.f, false);
   EXPECT_EQ(active_layer()->tilings()->NumHighResTilings(), 1);
 }
 
+TEST_F(PictureLayerImplTest, ScaledBoundsOverflowInt) {
+  // Limit visible size.
+  gfx::Size viewport_size(1, 1);
+  host_impl()->SetViewportSize(viewport_size);
+
+  gfx::Size layer_bounds(600000, 60);
+
+  // Set up the high and low res tilings before pinch zoom.
+  SetupDefaultTrees(layer_bounds);
+  ResetTilingsAndRasterScales();
+  EXPECT_EQ(0u, active_layer()->tilings()->num_tilings());
+  float scale = 8000.f;
+
+  // Verify this will overflow an int.
+  EXPECT_GT(static_cast<float>(layer_bounds.width()) * scale,
+            static_cast<float>(std::numeric_limits<int>::max()));
+
+  SetContentsScaleOnBothLayers(scale, 1.0f, scale, 1.0f, 0.f, false);
+  float adjusted_scale = active_layer()->HighResTiling()->contents_scale();
+  EXPECT_LT(adjusted_scale, scale);
+
+  // PopulateSharedQuadState CHECKs for overflows.
+  // See http://crbug.com/679035
+  active_layer()->draw_properties().visible_layer_rect =
+      gfx::Rect(layer_bounds);
+  SharedQuadState state;
+  active_layer()->PopulateScaledSharedQuadState(&state, adjusted_scale,
+                                                adjusted_scale);
+}
+
 TEST_F(PictureLayerImplTest, PinchGestureTilings) {
   gfx::Size layer_bounds(1300, 1900);
 
   float low_res_factor = host_impl()->settings().low_res_contents_scale_factor;
   // Set up the high and low res tilings before pinch zoom.
   SetupDefaultTrees(layer_bounds);
   ResetTilingsAndRasterScales();
 
   SetContentsScaleOnBothLayers(2.f, 1.0f, 2.f, 1.0f, 0.f, false);
   EXPECT_EQ(active_layer()->num_tilings(), 2u);
@@ skipping 4200 matching lines @@
     EXPECT_FLOAT_EQ(expected_contents_scale,
                     pending_layer_ptr->picture_layer_tiling_set()
                         ->FindTilingWithResolution(HIGH_RESOLUTION)
                         ->contents_scale())
         << "ideal_contents_scale: " << ideal_contents_scale;
   }
 }
 
 }  // namespace
 }  // namespace cc