Part 3/3 (RWH/IOSurface) of adding with device scale factor to transport surfaces

content/browser/renderer_host/render_widget_host_impl.cc

Index: content/browser/renderer_host/render_widget_host_impl.cc
diff --git a/content/browser/renderer_host/render_widget_host_impl.cc b/content/browser/renderer_host/render_widget_host_impl.cc
index 81833d15ce6a97412e9f90d9fa56f632504fb814..73652f023e27f3afed577d177ab2df14383d8a33 100644
--- a/content/browser/renderer_host/render_widget_host_impl.cc
+++ b/content/browser/renderer_host/render_widget_host_impl.cc
@@ -1647,28 +1647,25 @@ void RenderWidgetHostImpl::OnPaintAtSizeAck(int tag, const gfx::Size& size) {
 }
 
 void RenderWidgetHostImpl::OnCompositorSurfaceBuffersSwapped(
-      int32 surface_id,
-      uint64 surface_handle,
-      int32 route_id,
-      const gfx::Size& size,
-      int32 gpu_process_host_id) {
+      const ViewHostMsg_CompositorSurfaceBuffersSwapped_Params& params) {
   TRACE_EVENT0("renderer_host",
                "RenderWidgetHostImpl::OnCompositorSurfaceBuffersSwapped");
   if (!view_) {
     AcceleratedSurfaceMsg_BufferPresented_Params ack_params;
     ack_params.sync_point = 0;
-    RenderWidgetHostImpl::AcknowledgeBufferPresent(route_id,
-                                                   gpu_process_host_id,
+    RenderWidgetHostImpl::AcknowledgeBufferPresent(params.route_id,
+                                                   params.gpu_process_host_id,
                                                    ack_params);
     return;
   }
   GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params gpu_params;
-  gpu_params.surface_id = surface_id;
-  gpu_params.surface_handle = surface_handle;
-  gpu_params.route_id = route_id;
-  gpu_params.size = size;
+  gpu_params.surface_id = params.surface_id;
+  gpu_params.surface_handle = params.surface_handle;
+  gpu_params.route_id = params.route_id;
+  gpu_params.size = params.size;
+  gpu_params.scale_factor = params.scale_factor;

[Chris Evans, 2013/05/22 22:30:30]

This new parameter looks to come from the untrusted renderer. Before landing,
can you make sure nothing dies horribly with weird float values (inf, nan,
negatives, tiny fractions, huge numbers).

[ccameron, 2013/05/23 00:19:59]

We scale gpu_params.size by 1/scale_factor, which can result in messy values.
Those values aren't used to index into arrays, or anything that would obviously
go wrong (they're used as vertex coordinates, so strange values would be
clipped).

I tried inserting some bad values (nan, inf, 0, and -1), and the result was that
the contents area turned a solid color (which is about expected).

   view_->AcceleratedSurfaceBuffersSwapped(gpu_params,
-                                          gpu_process_host_id);
+                                          params.gpu_process_host_id);
 }
 
 bool RenderWidgetHostImpl::OnSwapCompositorFrame(