Add initial GLImage tracing + stubs

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 a1d54b7b365c2f4485e71dfe0bd38a63402556d5..92ffe086bb159c09ef628665e6e0e597ef921d64 100644
--- a/content/browser/gpu/browser_gpu_memory_buffer_manager.cc
+++ b/content/browser/gpu/browser_gpu_memory_buffer_manager.cc
@@ -14,6 +14,7 @@
 #include "base/trace_event/trace_event.h"
 #include "content/browser/gpu/gpu_process_host.h"
 #include "content/common/child_process_host_impl.h"
+#include "content/common/generic_shared_memory_id_generator.h"
 #include "content/common/gpu/client/gpu_memory_buffer_impl.h"
 #include "content/common/gpu/client/gpu_memory_buffer_impl_shared_memory.h"
 #include "content/common/gpu/gpu_memory_buffer_factory_shared_memory.h"
@@ -120,9 +121,6 @@ GetSupportedGpuMemoryBufferConfigurations(gfx::GpuMemoryBufferType type) {
 
 BrowserGpuMemoryBufferManager* g_gpu_memory_buffer_manager = nullptr;
 
-// Global atomic to generate gpu memory buffer unique IDs.
-base::StaticAtomicSequenceNumber g_next_gpu_memory_buffer_id;
-
 }  // namespace
 
 struct BrowserGpuMemoryBufferManager::AllocateGpuMemoryBufferRequest {
@@ -213,6 +211,7 @@ BrowserGpuMemoryBufferManager::AllocateGpuMemoryBufferForScanout(
 }
 
 void BrowserGpuMemoryBufferManager::AllocateGpuMemoryBufferForChildProcess(
+    gfx::GpuMemoryBufferId id,
     const gfx::Size& size,
     gfx::BufferFormat format,
     gfx::BufferUsage usage,
@@ -221,11 +220,9 @@ void BrowserGpuMemoryBufferManager::AllocateGpuMemoryBufferForChildProcess(
     const AllocationCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
-  gfx::GpuMemoryBufferId new_id = g_next_gpu_memory_buffer_id.GetNext();
-
   // Use service side allocation if this is a supported configuration.
   if (IsGpuMemoryBufferConfigurationSupported(format, usage)) {
-    AllocateGpuMemoryBufferOnIO(new_id, size, format, usage, child_client_id, 0,
+    AllocateGpuMemoryBufferOnIO(id, size, format, usage, child_client_id, 0,
                                 false, callback);
     return;
   }
@@ -239,13 +236,12 @@ void BrowserGpuMemoryBufferManager::AllocateGpuMemoryBufferForChildProcess(
   }
 
   BufferMap& buffers = clients_[child_client_id];
-  DCHECK(buffers.find(new_id) == buffers.end());
+  DCHECK(buffers.find(id) == buffers.end());
 
   // Allocate shared memory buffer as fallback.
-  buffers[new_id] =
-      BufferInfo(size, gfx::SHARED_MEMORY_BUFFER, format, usage, 0);
+  buffers[id] = BufferInfo(size, gfx::SHARED_MEMORY_BUFFER, format, usage, 0);
   callback.Run(GpuMemoryBufferImplSharedMemory::AllocateForChildProcess(
-      new_id, size, format, child_process_handle));
+      id, size, format, child_process_handle));
 }
 
 gfx::GpuMemoryBuffer*
@@ -291,17 +287,31 @@ bool BrowserGpuMemoryBufferManager::OnMemoryDump(
                       base::trace_event::MemoryAllocatorDump::kUnitsBytes,
                       buffer_size_in_bytes);
 
+      uint64 client_tracing_process_id = ClientIdToTracingProcessId(client_id);
+
       // Create the cross-process ownership edge. If the client creates a
       // 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.
-      uint64 client_tracing_process_id = ClientIdToTracingProcessId(client_id);
-
       base::trace_event::MemoryAllocatorDumpGuid shared_buffer_guid =
           gfx::GetGpuMemoryBufferGUIDForTracing(client_tracing_process_id,
                                                 buffer_id);
       pmd->CreateSharedGlobalAllocatorDump(shared_buffer_guid);
       pmd->AddOwnershipEdge(dump->guid(), shared_buffer_guid);
+
+      // Create an additional shared ownership edge with the generic shared
+      // memory id for the shared memory which backs this GpuMemoryBuffer.
+      base::trace_event::MemoryAllocatorDumpGuid shared_memory_guid =
+          base::trace_event::GetGenericSharedMemoryGUIDForTracing(
+              client_tracing_process_id, buffer_id);
+      pmd->CreateSharedGlobalAllocatorDump(shared_memory_guid);
+
+      // The link from the shared memory guid to the gpu memory buffer guid is
+      // set higher than the link from the shared memory guid to its various
+      // dumps. This ensures that memory is tracked with the gpu memory buffer.
+      const int kImportance = 2;
+      pmd->AddOwnershipEdge(shared_buffer_guid, shared_memory_guid,
+                            kImportance);
     }
   }
 
@@ -382,7 +392,7 @@ void BrowserGpuMemoryBufferManager::AllocateGpuMemoryBufferForSurfaceOnIO(
     AllocateGpuMemoryBufferRequest* request) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
-  gfx::GpuMemoryBufferId new_id = g_next_gpu_memory_buffer_id.GetNext();
+  gfx::GpuMemoryBufferId new_id = content::GetNextGenericSharedMemoryId();
 
   // Use service side allocation if this is a supported configuration.
   if (IsGpuMemoryBufferConfigurationSupported(request->format,