Add initial GLImage tracing + stubs

gpu/command_buffer/service/texture_manager.cc

Index: gpu/command_buffer/service/texture_manager.cc
diff --git a/gpu/command_buffer/service/texture_manager.cc b/gpu/command_buffer/service/texture_manager.cc
index a31a5f7c70a43164798b91e13862734d3b3b4fe4..b88f6bc6656c48d7339cc878ffb6a879f204bd15 100644
--- a/gpu/command_buffer/service/texture_manager.cc
+++ b/gpu/command_buffer/service/texture_manager.cc
@@ -2059,10 +2059,6 @@ bool TextureManager::OnMemoryDump(base::trace_event::ProcessMemoryDump* pmd) {
 
 void TextureManager::DumpTextureRef(base::trace_event::ProcessMemoryDump* pmd,
                                     TextureRef* ref) {
-  // TODO(ericrk): Trace image-backed textures. crbug.com/514914
-  if (ref->texture()->HasImages())
-    return;
-
   uint32_t size = ref->texture()->estimated_size();
 
   // Ignore unallocated texture IDs.
@@ -2072,6 +2068,15 @@ void TextureManager::DumpTextureRef(base::trace_event::ProcessMemoryDump* pmd,
   std::string dump_name =
       base::StringPrintf("gl/textures/client_%d/texture_%d",
                          memory_tracker_->ClientId(), ref->client_id());
+
+  // TODO(ericrk): GLImage tracing. crbug.com/514914
+  if (ref->texture()->HasImages()) {
+    ref->texture()
+        ->GetLevelImage(GL_TEXTURE_2D, 0)
+        ->DumpMemory(pmd, memory_tracker_->ClientTracingId(), dump_name);
+    return;
+  }
+
   base::trace_event::MemoryAllocatorDump* dump =
       pmd->CreateAllocatorDump(dump_name);
   dump->AddScalar(base::trace_event::MemoryAllocatorDump::kNameSize,