cc: Use CheckedNumeric for resource size calculations.

cc/trees/layer_tree_host.cc

Index: cc/trees/layer_tree_host.cc
diff --git a/cc/trees/layer_tree_host.cc b/cc/trees/layer_tree_host.cc
index a0f279a1492f5d3a5a7982fac4e50545a504f9f5..02f80350cd9939a436f1014a70c63b4ba6eaca29 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -933,9 +933,10 @@ size_t LayerTreeHost::CalculateMemoryForRenderSurfaces(
     Layer* render_surface_layer = update_list.at(i);
     RenderSurface* render_surface = render_surface_layer->render_surface();
 
-    size_t bytes =
-        Resource::MemorySizeBytes(render_surface->content_rect().size(),
-                                  RGBA_8888);
+    // We can use UncheckedMemorySizeBytes, since render surface content rect is
+    // limited by max texture size.
+    size_t bytes = Resource::UncheckedMemorySizeBytes(
+        render_surface->content_rect().size(), RGBA_8888);
     contents_texture_bytes += bytes;
 
     if (render_surface_layer->background_filters().IsEmpty() &&
@@ -943,8 +944,10 @@ size_t LayerTreeHost::CalculateMemoryForRenderSurfaces(
       continue;
 
     if (!readback_bytes) {
-      readback_bytes = Resource::MemorySizeBytes(device_viewport_size_,
-                                                 RGBA_8888);
+      // We need to use a checked size calucation here, since we don't control
+      // the size of the device viewport.
+      readback_bytes =
+          Resource::CheckedMemorySizeBytes(device_viewport_size_, RGBA_8888);
     }
   }
   return readback_bytes + contents_texture_bytes;