Add generated and hand-written passthrough command handlers with stub Doers.

gpu/command_buffer/common/buffer.cc

Index: gpu/command_buffer/common/buffer.cc
diff --git a/gpu/command_buffer/common/buffer.cc b/gpu/command_buffer/common/buffer.cc
index 1bb9523079dd3c094685b9ad306df7697b7526eb..9e8d5a0962bda741f5f62a4ba15bfd30b9d65cdc 100644
--- a/gpu/command_buffer/common/buffer.cc
+++ b/gpu/command_buffer/common/buffer.cc
@@ -43,6 +43,21 @@ void* Buffer::GetDataAddress(uint32_t data_offset, uint32_t data_size) const {
   return static_cast<uint8_t*>(memory_) + data_offset;
 }
 
+void* Buffer::GetDataAddressAndSize(uint32_t data_offset,
+                                    uint32_t* data_size) const {
+  if (data_offset > static_cast<uint32_t>(size_))
+    return NULL;
+  *data_size = GetRemainingSize(data_offset);
+  return static_cast<uint8_t*>(memory_) + data_offset;
+}
+
+uint32_t Buffer::GetRemainingSize(uint32_t data_offset) const {
+  base::CheckedNumeric<uint32_t> offset = data_offset;
+  if (!offset.IsValid() || offset.ValueOrDie() > static_cast<uint32_t>(size_))

[piman, 2016/05/25 23:34:42]

Not sure of the goal of the offset.IsValid() check here. data_offset is a
uint32_t, so moving into a CheckedNumeric<uint32_t> will always be valid.

[Geoff Lang, 2016/05/27 14:31:28]

Whoops, yes, forgot to remove the CheckedNumerics from both functions.

+    return 0;
+  return static_cast<uint32_t>(size_) - data_offset;
+}
+
 base::trace_event::MemoryAllocatorDumpGuid GetBufferGUIDForTracing(
     uint64_t tracing_process_id,
     int32_t buffer_id) {