content: Move type selection logic out of GpuMemoryBufferImpl.

content/common/child_process_host_impl.cc

Index: content/common/child_process_host_impl.cc
diff --git a/content/common/child_process_host_impl.cc b/content/common/child_process_host_impl.cc
index 8e1f56f694f2983140c40eefa89d37ebd8a40f71..5c8cdb66be3ed2ffd67258daaeb63b5114793f5e 100644
--- a/content/common/child_process_host_impl.cc
+++ b/content/common/child_process_host_impl.cc
@@ -320,16 +320,9 @@ void ChildProcessHostImpl::OnAllocateGpuMemoryBuffer(
     gfx::GpuMemoryBuffer::Format format,
     gfx::GpuMemoryBuffer::Usage usage,
     IPC::Message* reply) {
-  base::CheckedNumeric<int> size = width;
-  size *= height;
-  if (!size.IsValid()) {

[piman, 2014/11/11 22:38:30]

Why removing this?

[reveman, 2014/11/12 05:09:20]

This check is now done by
GpuMemoryBufferImplSharedMemory::AllocateForChildProcess. The reasoning is that
only ::AllocateForChildProcess implementations can know what values can cause
problems. In the SharedMemory case, bbp * width * height overflow is what we
need to check for but that could be different for other implementations.

[piman, 2014/11/14 03:59:44]

Ok, can you add a comment? It's generally good to have checks closer to the IPC
handlers, because that's where the security decisions are usually taken. If it's
in other places it's easy to lose the checks during refactoring etc.

[reveman, 2014/11/17 02:26:53]

Done.

-    GpuMemoryBufferAllocated(reply, gfx::GpuMemoryBufferHandle());
-    return;
-  }
-
   // TODO(reveman): Add support for other types of GpuMemoryBuffers.
-  if (!GpuMemoryBufferImplSharedMemory::IsConfigurationSupported(
-          gfx::Size(width, height), format, usage)) {
+  if (!GpuMemoryBufferImplSharedMemory::IsFormatSupported(format) ||
+      !GpuMemoryBufferImplSharedMemory::IsUsageSupported(usage)) {
     GpuMemoryBufferAllocated(reply, gfx::GpuMemoryBufferHandle());
     return;
   }