content/gpu: Simplify gpu channel message handling.

content/common/gpu/gpu_channel_manager.cc

Index: content/common/gpu/gpu_channel_manager.cc
diff --git a/content/common/gpu/gpu_channel_manager.cc b/content/common/gpu/gpu_channel_manager.cc
index 0359393f1ae0f1075585f4c21ffdf04b4248641a..99415185a7a33089533623b68a1451ce23134dc4 100644
--- a/content/common/gpu/gpu_channel_manager.cc
+++ b/content/common/gpu/gpu_channel_manager.cc
@@ -107,7 +107,7 @@ void GpuChannelManager::RemoveRoute(int32 routing_id) {
   router_.RemoveRoute(routing_id);
 }
 
-GpuChannel* GpuChannelManager::LookupChannel(int32 client_id) {
+GpuChannel* GpuChannelManager::LookupChannel(int32 client_id) const {
   const auto& it = gpu_channels_.find(client_id);
   return it != gpu_channels_.end() ? it->second : nullptr;
 }
@@ -251,16 +251,7 @@ void GpuChannelManager::OnLoadedShader(std::string program_proto) {
     program_cache()->LoadProgram(program_proto);
 }
 
-uint32_t GpuChannelManager::ProcessedOrderNumber() {
-  uint32_t processed_order_num = 0;
-  for (auto& kv : gpu_channels_) {
-    processed_order_num =
-        std::max(processed_order_num, kv.second->GetProcessedOrderNum());
-  }
-  return processed_order_num;
-}
-
-uint32_t GpuChannelManager::UnprocessedOrderNumber() {
+uint32_t GpuChannelManager::GetUnprocessedOrderNum() const {
   uint32_t unprocessed_order_num = 0;
   for (auto& kv : gpu_channels_) {
     unprocessed_order_num =
@@ -269,6 +260,15 @@ uint32_t GpuChannelManager::UnprocessedOrderNumber() {
   return unprocessed_order_num;
 }
 
+uint32_t GpuChannelManager::GetProcessedOrderNum() const {
+  uint32_t processed_order_num = 0;
+  for (auto& kv : gpu_channels_) {
+    processed_order_num =
+        std::max(processed_order_num, kv.second->GetProcessedOrderNum());
+  }
+  return processed_order_num;
+}
+
 void GpuChannelManager::LoseAllContexts() {
   for (auto& kv : gpu_channels_) {
     kv.second->MarkAllContextsLost();