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..c302180902dc7504d95df09d3e49a4ba814fd401 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);
+    CHECK(Resource::VerifySizeInBytes(render_surface->content_rect().size(),

[vmpstr, 2015/06/04 20:52:59]

I wasn't sure about this function, so I think it's better to CHECK than not? Let
me know.

[danakj, 2015/06/04 20:58:44]

RenderSurface content rects are bounded by the max texture size which is small.

+                                      RGBA_8888));
+    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 +944,9 @@ size_t LayerTreeHost::CalculateMemoryForRenderSurfaces(
       continue;
 
     if (!readback_bytes) {
-      readback_bytes = Resource::MemorySizeBytes(device_viewport_size_,
-                                                 RGBA_8888);
+      CHECK(Resource::VerifySizeInBytes(device_viewport_size_, RGBA_8888));

[danakj, 2015/06/04 20:58:44]

This is correct to check about I think it comes from outside cc and is somewhat
opaque to us. How about adding a Resource::CheckedMemorySizeBytes that does
ValueOrDie()?

+      readback_bytes =
+          Resource::UncheckedMemorySizeBytes(device_viewport_size_, RGBA_8888);
     }
   }
   return readback_bytes + contents_texture_bytes;