Add tracing for GL texture objects

content/browser/gpu/browser_gpu_memory_buffer_manager.cc

Index: content/browser/gpu/browser_gpu_memory_buffer_manager.cc
diff --git a/content/browser/gpu/browser_gpu_memory_buffer_manager.cc b/content/browser/gpu/browser_gpu_memory_buffer_manager.cc
index 67797d42937129b8dcc17254764621bb84db3316..94c07ef755c732b63a356c6ac0e783c71c7c07e9 100644
--- a/content/browser/gpu/browser_gpu_memory_buffer_manager.cc
+++ b/content/browser/gpu/browser_gpu_memory_buffer_manager.cc
@@ -294,8 +294,8 @@ bool BrowserGpuMemoryBufferManager::OnMemoryDump(
       // corresponding dump for the same buffer, this will avoid to
       // double-count them in tracing. If, instead, no other process will emit a
       // dump with the same guid, the segment will be accounted to the browser.
-      const uint64 client_tracing_process_id = base::trace_event::
-          MemoryDumpManager::ChildProcessIdToTracingProcessId(client_id);
+      uint64 client_tracing_process_id = ClientIdToTracingProcessId(client_id);
+
       base::trace_event::MemoryAllocatorDumpGuid shared_buffer_guid =
           gfx::GetGpuMemoryBufferGUIDForTracing(client_tracing_process_id,
                                                 buffer_id);
@@ -590,4 +590,20 @@ void BrowserGpuMemoryBufferManager::DestroyGpuMemoryBufferOnIO(
   buffers.erase(buffer_it);
 }
 
+uint64_t BrowserGpuMemoryBufferManager::ClientIdToTracingProcessId(
+    int client_id) const {
+  if (client_id == gpu_client_id_) {
+    // The browser process doesn't use a client ID to generate its tracing ID.
+    // Instead it uses a fixed tracing ID. If |client_id| == |gpu_client_id_|,
+    // then this surface is owned by the browser, so get our current tracing ID.
+    return base::trace_event::MemoryDumpManager::GetInstance()
+        ->tracing_process_id();

[reveman, 2015/07/29 19:41:19]

nit: Please add a "const int gpu_client_tracing_id_" member that is set in the
ctor instead of calling this here. The comment can then be moved to the
BrowserGpuChannelHostFactory ctor where we have this logic already.

[ericrk, 2015/07/29 21:37:46]

good point. done.

+  } else {

[reveman, 2015/07/29 19:41:19]

nit: maybe skip this else statement as you return above in the if scope

[ericrk, 2015/07/29 21:37:46]

Done.

+    // In normal cases, |client_id| is a child process id, so we can perform
+    // the standard conversion.
+    return base::trace_event::MemoryDumpManager::
+        ChildProcessIdToTracingProcessId(client_id);
+  }
+}
+
 }  // namespace content