Add GenericSharedMemoryId and use w/ GpuMemoryBuffer

Adds a GenericSharedMemoryId type which will be used to track various types of shared memory (SharedBitmap, IOSurface, base::SharedMemory).

Wire up GpuMemoryBufferManager so that GpuMemoryBufferId is just a typedef of this type, setting up for further integration in the future.

Note regarding message changes - We needed a way for all GenericSharedMemoryIds used by a process to be unique. Currently a renderer process sometimes internally allocates shared memory and sometimes asks the browser process to do so. In order to allow for consistent naming, we cause the Renderer process to provide an ID to the browser when asking the browser to allocate on its behalf.

+tsepez for message changes.
+piman for content/gpu changes
+danakj/reveman for other changes.

TBR=sky@chromium.org
BUG=512534
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1280513002

Cr-Commit-Position: refs/heads/master@{#343677}

34 files changed, 218 insertions, 72 deletions

diff --git a/cc/test/test_gpu_memory_buffer_manager.cc b/cc/test/test_gpu_memory_buffer_manager.cc
index 6648823..8d56a97 100644
--- a/cc/test/test_gpu_memory_buffer_manager.cc
+++ b/cc/test/test_gpu_memory_buffer_manager.cc
@@ -123,7 +123,7 @@ class GpuMemoryBufferImpl : public gfx::GpuMemoryBuffer {
   }
   gfx::GpuMemoryBufferId GetId() const override {
     NOTREACHED();
-    return 0;
+    return gfx::GpuMemoryBufferId(0);
   }
   gfx::GpuMemoryBufferHandle GetHandle() const override {
     gfx::GpuMemoryBufferHandle handle;
diff --git a/components/view_manager/gles2/command_buffer_driver.cc b/components/view_manager/gles2/command_buffer_driver.cc
index cbb63dc..5a4ac83f 100644
--- a/components/view_manager/gles2/command_buffer_driver.cc
+++ b/components/view_manager/gles2/command_buffer_driver.cc
@@ -256,7 +256,7 @@ void CommandBufferDriver::CreateImage(int32_t id,
   gfx::GpuMemoryBufferHandle gfx_handle;
   // TODO(jam): create mojo enum for this and converter
   gfx_handle.type = static_cast<gfx::GpuMemoryBufferType>(type);
-  gfx_handle.id = id;
+  gfx_handle.id = gfx::GpuMemoryBufferId(id);
 
   MojoPlatformHandle platform_handle;
   MojoResult extract_result = MojoExtractPlatformHandle(
diff --git a/components/view_manager/gles2/mojo_gpu_memory_buffer.cc b/components/view_manager/gles2/mojo_gpu_memory_buffer.cc
index 5f6a2864..0efa398 100644
--- a/components/view_manager/gles2/mojo_gpu_memory_buffer.cc
+++ b/components/view_manager/gles2/mojo_gpu_memory_buffer.cc
@@ -152,7 +152,7 @@ void MojoGpuMemoryBufferImpl::GetStride(int* stride) const {
 }
 
 gfx::GpuMemoryBufferId MojoGpuMemoryBufferImpl::GetId() const {
-  return 0;
+  return gfx::GpuMemoryBufferId(0);
 }
 
 gfx::GpuMemoryBufferHandle MojoGpuMemoryBufferImpl::GetHandle() const {
diff --git a/content/browser/browser_io_surface_manager_mac.h b/content/browser/browser_io_surface_manager_mac.h
index 7d786eb..62ae750 100644
--- a/content/browser/browser_io_surface_manager_mac.h
+++ b/content/browser/browser_io_surface_manager_mac.h
@@ -24,6 +24,11 @@
 
 namespace content {
 
+// TODO(ericrk): Use gfx::GenericSharedMemoryId as the |io_surface_id| in
+// this file. Allows for more type-safe usage of GpuMemoryBufferIds as the
+// type of the |io_surface_id|, as it is a typedef of
+// gfx::GenericSharedMemoryId.
+
 // Implementation of IOSurfaceManager that provides a mechanism for child
 // processes to register and acquire IOSurfaces through a Mach service.
 class CONTENT_EXPORT BrowserIOSurfaceManager : public IOSurfaceManager {
diff --git a/content/browser/compositor/buffer_queue_unittest.cc b/content/browser/compositor/buffer_queue_unittest.cc
index 4c52a8e..0fe4173 100644
--- a/content/browser/compositor/buffer_queue_unittest.cc
+++ b/content/browser/compositor/buffer_queue_unittest.cc
@@ -34,7 +34,9 @@ class StubGpuMemoryBufferImpl : public gfx::GpuMemoryBuffer {
     return gfx::BufferFormat::RGBX_8888;
   }
   void GetStride(int* stride) const override {}
-  gfx::GpuMemoryBufferId GetId() const override { return 0; }
+  gfx::GpuMemoryBufferId GetId() const override {
+    return gfx::GpuMemoryBufferId(0);
+  }
   gfx::GpuMemoryBufferHandle GetHandle() const override {
     return gfx::GpuMemoryBufferHandle();
   }
diff --git a/content/browser/gpu/browser_gpu_memory_buffer_manager.cc b/content/browser/gpu/browser_gpu_memory_buffer_manager.cc
index 3770c762..99394ac 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"
@@ -141,9 +142,6 @@ 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 {
@@ -234,6 +232,7 @@ BrowserGpuMemoryBufferManager::AllocateGpuMemoryBufferForScanout(
 }
 
 void BrowserGpuMemoryBufferManager::AllocateGpuMemoryBufferForChildProcess(
+    gfx::GpuMemoryBufferId id,
     const gfx::Size& size,
     gfx::BufferFormat format,
     gfx::BufferUsage usage,
@@ -242,11 +241,9 @@ 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;
   }
@@ -260,13 +257,19 @@ void BrowserGpuMemoryBufferManager::AllocateGpuMemoryBufferForChildProcess(
   }
 
   BufferMap& buffers = clients_[child_client_id];
-  DCHECK(buffers.find(new_id) == buffers.end());
 
   // Allocate shared memory buffer as fallback.
-  buffers[new_id] =
-      BufferInfo(size, gfx::SHARED_MEMORY_BUFFER, format, usage, 0);
+  auto insert_result = buffers.insert(std::make_pair(
+      id, BufferInfo(size, gfx::SHARED_MEMORY_BUFFER, format, usage, 0)));
+  if (!insert_result.second) {
+    DLOG(ERROR) << "Child process attempted to allocate a GpuMemoryBuffer with "
+                   "an existing ID.";
+    callback.Run(gfx::GpuMemoryBufferHandle());
+    return;
+  }
+
   callback.Run(GpuMemoryBufferImplSharedMemory::AllocateForChildProcess(
-      new_id, size, format, child_process_handle));
+      id, size, format, child_process_handle));
 }
 
 gfx::GpuMemoryBuffer*
@@ -297,7 +300,7 @@ bool BrowserGpuMemoryBufferManager::OnMemoryDump(
       gfx::GpuMemoryBufferId buffer_id = buffer.first;
       base::trace_event::MemoryAllocatorDump* dump =
           pmd->CreateAllocatorDump(base::StringPrintf(
-              "gpumemorybuffer/client_%d/buffer_%d", client_id, buffer_id));
+              "gpumemorybuffer/client_%d/buffer_%d", client_id, buffer_id.id));
       if (!dump)
         return false;
 
@@ -404,7 +407,7 @@ 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,
@@ -426,11 +429,13 @@ void BrowserGpuMemoryBufferManager::AllocateGpuMemoryBufferForSurfaceOnIO(
       << static_cast<int>(request->usage);
 
   BufferMap& buffers = clients_[request->client_id];
-  DCHECK(buffers.find(new_id) == buffers.end());
 
   // Allocate shared memory buffer as fallback.
-  buffers[new_id] = BufferInfo(request->size, gfx::SHARED_MEMORY_BUFFER,
-                               request->format, request->usage, 0);
+  auto insert_result = buffers.insert(std::make_pair(
+      new_id, BufferInfo(request->size, gfx::SHARED_MEMORY_BUFFER,
+                         request->format, request->usage, 0)));
+  DCHECK(insert_result.second);
+
   // Note: Unretained is safe as IO thread is stopped before manager is
   // destroyed.
   request->result = GpuMemoryBufferImplSharedMemory::Create(
@@ -477,9 +482,6 @@ void BrowserGpuMemoryBufferManager::AllocateGpuMemoryBufferOnIO(
     const AllocationCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
-  BufferMap& buffers = clients_[client_id];
-  DCHECK(buffers.find(id) == buffers.end());
-
   GpuProcessHost* host = GpuProcessHost::FromID(gpu_host_id_);
   if (!host) {
     host = GpuProcessHost::Get(GpuProcessHost::GPU_PROCESS_KIND_SANDBOXED,
@@ -504,10 +506,19 @@ void BrowserGpuMemoryBufferManager::AllocateGpuMemoryBufferOnIO(
     reused_gpu_process = true;
   }
 
+  BufferMap& buffers = clients_[client_id];
+
   // Note: Handling of cases where the client is removed before the allocation
   // completes is less subtle if we set the buffer type to EMPTY_BUFFER here
   // and verify that this has not changed when allocation completes.
-  buffers[id] = BufferInfo(size, gfx::EMPTY_BUFFER, format, usage, 0);
+  auto insert_result = buffers.insert(std::make_pair(
+      id, BufferInfo(size, gfx::EMPTY_BUFFER, format, usage, 0)));
+  if (!insert_result.second) {
+    DLOG(ERROR) << "Child process attempted to allocate a GpuMemoryBuffer with "
+                   "an existing ID.";
+    callback.Run(gfx::GpuMemoryBufferHandle());
+    return;
+  }
 
   // Note: Unretained is safe as IO thread is stopped before manager is
   // destroyed.
diff --git a/content/browser/gpu/browser_gpu_memory_buffer_manager.h b/content/browser/gpu/browser_gpu_memory_buffer_manager.h
index b11faf8..12fd082 100644
--- a/content/browser/gpu/browser_gpu_memory_buffer_manager.h
+++ b/content/browser/gpu/browser_gpu_memory_buffer_manager.h
@@ -52,6 +52,7 @@ class CONTENT_EXPORT BrowserGpuMemoryBufferManager
       int32 surface_id);
 
   void AllocateGpuMemoryBufferForChildProcess(
+      gfx::GpuMemoryBufferId id,
       const gfx::Size& size,
       gfx::BufferFormat format,
       gfx::BufferUsage usage,
diff --git a/content/browser/renderer_host/media/video_capture_buffer_pool_unittest.cc b/content/browser/renderer_host/media/video_capture_buffer_pool_unittest.cc
index a02aa93..7d5fce4 100644
--- a/content/browser/renderer_host/media/video_capture_buffer_pool_unittest.cc
+++ b/content/browser/renderer_host/media/video_capture_buffer_pool_unittest.cc
@@ -71,7 +71,9 @@ class VideoCaptureBufferPoolTest
       *stride = size_.width() * 4;
       return;
     }
-    gfx::GpuMemoryBufferId GetId() const override { return 0; }
+    gfx::GpuMemoryBufferId GetId() const override {
+      return gfx::GpuMemoryBufferId(0);
+    }
     gfx::GpuMemoryBufferHandle GetHandle() const override {
       return gfx::GpuMemoryBufferHandle();
     }
diff --git a/content/browser/renderer_host/render_message_filter.cc b/content/browser/renderer_host/render_message_filter.cc
index e2df8be..ce6572a 100644
--- a/content/browser/renderer_host/render_message_filter.cc
+++ b/content/browser/renderer_host/render_message_filter.cc
@@ -1199,7 +1199,8 @@ void RenderMessageFilter::OnWebAudioMediaCodec(
 }
 #endif
 
-void RenderMessageFilter::OnAllocateGpuMemoryBuffer(uint32 width,
+void RenderMessageFilter::OnAllocateGpuMemoryBuffer(gfx::GpuMemoryBufferId id,
+                                                    uint32 width,
                                                     uint32 height,
                                                     gfx::BufferFormat format,
                                                     gfx::BufferUsage usage,
@@ -1215,13 +1216,10 @@ void RenderMessageFilter::OnAllocateGpuMemoryBuffer(uint32 width,
 
   BrowserGpuMemoryBufferManager::current()
       ->AllocateGpuMemoryBufferForChildProcess(
-          gfx::Size(width, height),
-          format,
-          usage,
-          PeerHandle(),
+          id, gfx::Size(width, height), format, usage, PeerHandle(),
           render_process_id_,
-          base::Bind(
-              &RenderMessageFilter::GpuMemoryBufferAllocated, this, reply));
+          base::Bind(&RenderMessageFilter::GpuMemoryBufferAllocated, this,
+                     reply));
 }
 
 void RenderMessageFilter::GpuMemoryBufferAllocated(
diff --git a/content/browser/renderer_host/render_message_filter.h b/content/browser/renderer_host/render_message_filter.h
index 8ef5be9..6d8ac3a 100644
--- a/content/browser/renderer_host/render_message_filter.h
+++ b/content/browser/renderer_host/render_message_filter.h
@@ -292,7 +292,8 @@ class CONTENT_EXPORT RenderMessageFilter : public BrowserMessageFilter {
                             uint32_t data_size);
 #endif
 
-  void OnAllocateGpuMemoryBuffer(uint32 width,
+  void OnAllocateGpuMemoryBuffer(gfx::GpuMemoryBufferId id,
+                                 uint32 width,
                                  uint32 height,
                                  gfx::BufferFormat format,
                                  gfx::BufferUsage usage,
diff --git a/content/child/child_gpu_memory_buffer_manager.cc b/content/child/child_gpu_memory_buffer_manager.cc
index 9a7517d..1c7b67b 100644
--- a/content/child/child_gpu_memory_buffer_manager.cc
+++ b/content/child/child_gpu_memory_buffer_manager.cc
@@ -5,6 +5,7 @@
 #include "content/child/child_gpu_memory_buffer_manager.h"
 
 #include "content/common/child_process_messages.h"
+#include "content/common/generic_shared_memory_id_generator.h"
 #include "content/common/gpu/client/gpu_memory_buffer_impl.h"
 
 namespace content {
@@ -41,7 +42,8 @@ ChildGpuMemoryBufferManager::AllocateGpuMemoryBuffer(const gfx::Size& size,
 
   gfx::GpuMemoryBufferHandle handle;
   IPC::Message* message = new ChildProcessHostMsg_SyncAllocateGpuMemoryBuffer(
-      size.width(), size.height(), format, usage, &handle);
+      content::GetNextGenericSharedMemoryId(), size.width(), size.height(),
+      format, usage, &handle);
   bool success = sender_->Send(message);
   if (!success || handle.is_null())
     return nullptr;
diff --git a/content/common/child_process_host_impl.cc b/content/common/child_process_host_impl.cc
index 67004c1..3aad503 100644
--- a/content/common/child_process_host_impl.cc
+++ b/content/common/child_process_host_impl.cc
@@ -87,9 +87,6 @@ base::FilePath TransformPathForFeature(const base::FilePath& path,
 // Global atomic to generate child process unique IDs.
 base::StaticAtomicSequenceNumber g_unique_id;
 
-// Global atomic to generate gpu memory buffer unique IDs.
-base::StaticAtomicSequenceNumber g_next_gpu_memory_buffer_id;
-
 }  // namespace
 
 namespace content {
@@ -358,6 +355,7 @@ void ChildProcessHostImpl::OnShutdownRequest() {
 }
 
 void ChildProcessHostImpl::OnAllocateGpuMemoryBuffer(
+    gfx::GpuMemoryBufferId id,
     uint32 width,
     uint32 height,
     gfx::BufferFormat format,
@@ -371,8 +369,7 @@ void ChildProcessHostImpl::OnAllocateGpuMemoryBuffer(
   if (GpuMemoryBufferImplSharedMemory::IsFormatSupported(format) &&
       GpuMemoryBufferImplSharedMemory::IsUsageSupported(usage)) {
     *handle = GpuMemoryBufferImplSharedMemory::AllocateForChildProcess(
-        g_next_gpu_memory_buffer_id.GetNext(), gfx::Size(width, height), format,
-        peer_process_.Handle());
+        id, gfx::Size(width, height), format, peer_process_.Handle());
   }
 }
 
diff --git a/content/common/child_process_host_impl.h b/content/common/child_process_host_impl.h
index dd1fae7..d859323 100644
--- a/content/common/child_process_host_impl.h
+++ b/content/common/child_process_host_impl.h
@@ -94,7 +94,8 @@ class CONTENT_EXPORT ChildProcessHostImpl : public ChildProcessHost,
   void OnShutdownRequest();
   void OnAllocateSharedMemory(uint32 buffer_size,
                               base::SharedMemoryHandle* handle);
-  void OnAllocateGpuMemoryBuffer(uint32 width,
+  void OnAllocateGpuMemoryBuffer(gfx::GpuMemoryBufferId id,
+                                 uint32 width,
                                  uint32 height,
                                  gfx::BufferFormat format,
                                  gfx::BufferUsage usage,
diff --git a/content/common/child_process_messages.h b/content/common/child_process_messages.h
index 896d864..5775054 100644
--- a/content/common/child_process_messages.h
+++ b/content/common/child_process_messages.h
@@ -70,6 +70,10 @@ IPC_STRUCT_TRAITS_BEGIN(gfx::GpuMemoryBufferHandle)
   IPC_STRUCT_TRAITS_MEMBER(handle)
 IPC_STRUCT_TRAITS_END()
 
+IPC_STRUCT_TRAITS_BEGIN(gfx::GpuMemoryBufferId)
+  IPC_STRUCT_TRAITS_MEMBER(id)
+IPC_STRUCT_TRAITS_END()
+
 #undef IPC_MESSAGE_EXPORT
 #define IPC_MESSAGE_EXPORT CONTENT_EXPORT
 
@@ -185,7 +189,8 @@ IPC_MESSAGE_CONTROL1(ChildProcessHostMsg_TcmallocStats,
 #endif
 
 // Asks the browser to create a gpu memory buffer.
-IPC_SYNC_MESSAGE_CONTROL4_1(ChildProcessHostMsg_SyncAllocateGpuMemoryBuffer,
+IPC_SYNC_MESSAGE_CONTROL5_1(ChildProcessHostMsg_SyncAllocateGpuMemoryBuffer,
+                            gfx::GpuMemoryBufferId /* new_id */,
                             uint32 /* width */,
                             uint32 /* height */,
                             gfx::BufferFormat,
diff --git a/content/common/generic_shared_memory_id_generator.cc b/content/common/generic_shared_memory_id_generator.cc
new file mode 100644
index 0000000..c912bc2
--- /dev/null
+++ b/content/common/generic_shared_memory_id_generator.cc
@@ -0,0 +1,21 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/common/generic_shared_memory_id_generator.h"
+
+#include "base/atomic_sequence_num.h"
+
+namespace content {
+namespace {
+
+// Global atomic to generate gpu memory buffer unique IDs.
+base::StaticAtomicSequenceNumber g_next_generic_shared_memory_id;
+
+}  // namespace
+
+gfx::GenericSharedMemoryId GetNextGenericSharedMemoryId() {
+  return gfx::GenericSharedMemoryId(g_next_generic_shared_memory_id.GetNext());
+}
+
+}  // namespace content
diff --git a/content/common/generic_shared_memory_id_generator.h b/content/common/generic_shared_memory_id_generator.h
new file mode 100644
index 0000000..4640cc1
--- /dev/null
+++ b/content/common/generic_shared_memory_id_generator.h
@@ -0,0 +1,19 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_COMMON_GENERIC_SHARED_MEMORY_ID_GENERATOR_H_
+#define CONTENT_COMMON_GENERIC_SHARED_MEMORY_ID_GENERATOR_H_
+
+#include "ui/gfx/generic_shared_memory_id.h"
+#include "content/common/content_export.h"
+
+namespace content {
+
+// Returns the next GenericSharedMemoryId for the current process. This should
+// be used anywhere a new GenericSharedMemoryId is needed.
+CONTENT_EXPORT gfx::GenericSharedMemoryId GetNextGenericSharedMemoryId();
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_GENERIC_SHARED_MEMORY_ID_GENERATOR_H_
diff --git a/content/common/gpu/client/gpu_memory_buffer_impl_io_surface.cc b/content/common/gpu/client/gpu_memory_buffer_impl_io_surface.cc
index 7a3f044..16c27c8 100644
--- a/content/common/gpu/client/gpu_memory_buffer_impl_io_surface.cc
+++ b/content/common/gpu/client/gpu_memory_buffer_impl_io_surface.cc
@@ -48,7 +48,7 @@ scoped_ptr<GpuMemoryBufferImpl> GpuMemoryBufferImplIOSurface::CreateFromHandle(
     gfx::BufferUsage usage,
     const DestructionCallback& callback) {
   base::ScopedCFTypeRef<IOSurfaceRef> io_surface(
-      IOSurfaceManager::GetInstance()->AcquireIOSurface(handle.id));
+      IOSurfaceManager::GetInstance()->AcquireIOSurface(handle.id.id));
   if (!io_surface)
     return nullptr;
 
diff --git a/content/common/gpu/client/gpu_memory_buffer_impl_surface_texture.cc b/content/common/gpu/client/gpu_memory_buffer_impl_surface_texture.cc
index d4d2ef2..2bbea50 100644
--- a/content/common/gpu/client/gpu_memory_buffer_impl_surface_texture.cc
+++ b/content/common/gpu/client/gpu_memory_buffer_impl_surface_texture.cc
@@ -58,8 +58,9 @@ GpuMemoryBufferImplSurfaceTexture::CreateFromHandle(
     const gfx::Size& size,
     gfx::BufferFormat format,
     const DestructionCallback& callback) {
-  ANativeWindow* native_window = SurfaceTextureManager::GetInstance()->
-      AcquireNativeWidgetForSurfaceTexture(handle.id);
+  ANativeWindow* native_window =
+      SurfaceTextureManager::GetInstance()
+          ->AcquireNativeWidgetForSurfaceTexture(handle.id.id);
   if (!native_window)
     return scoped_ptr<GpuMemoryBufferImpl>();
 
diff --git a/content/common/gpu/client/gpu_memory_buffer_impl_unittest.cc b/content/common/gpu/client/gpu_memory_buffer_impl_unittest.cc
index 1ab1d99..29fdd44 100644
--- a/content/common/gpu/client/gpu_memory_buffer_impl_unittest.cc
+++ b/content/common/gpu/client/gpu_memory_buffer_impl_unittest.cc
@@ -50,7 +50,7 @@ class GpuMemoryBufferImplTest
 };
 
 TEST_P(GpuMemoryBufferImplTest, CreateFromHandle) {
-  const int kBufferId = 1;
+  const gfx::GpuMemoryBufferId kBufferId(1);
 
   gfx::Size buffer_size(8, 8);
 
@@ -73,7 +73,7 @@ TEST_P(GpuMemoryBufferImplTest, CreateFromHandle) {
 }
 
 TEST_P(GpuMemoryBufferImplTest, Map) {
-  const int kBufferId = 1;
+  const gfx::GpuMemoryBufferId kBufferId(1);
 
   // Use a multiple of 4 for both dimensions to support compressed formats.
   gfx::Size buffer_size(4, 4);
@@ -135,7 +135,7 @@ TEST_P(GpuMemoryBufferImplTest, Map) {
 }
 
 TEST_P(GpuMemoryBufferImplTest, PersistentMap) {
-  const int kBufferId = 1;
+  const gfx::GpuMemoryBufferId kBufferId(1);
 
   // Use a multiple of 4 for both dimensions to support compressed formats.
   gfx::Size buffer_size(4, 4);
diff --git a/content/common/gpu/gpu_memory_buffer_factory_io_surface.cc b/content/common/gpu/gpu_memory_buffer_factory_io_surface.cc
index 1dd8cb4..41a9f5d 100644
--- a/content/common/gpu/gpu_memory_buffer_factory_io_surface.cc
+++ b/content/common/gpu/gpu_memory_buffer_factory_io_surface.cc
@@ -156,7 +156,7 @@ GpuMemoryBufferFactoryIOSurface::CreateGpuMemoryBuffer(
   if (!io_surface)
     return gfx::GpuMemoryBufferHandle();
 
-  if (!IOSurfaceManager::GetInstance()->RegisterIOSurface(id, client_id,
+  if (!IOSurfaceManager::GetInstance()->RegisterIOSurface(id.id, client_id,
                                                           io_surface)) {
     return gfx::GpuMemoryBufferHandle();
   }
@@ -164,7 +164,7 @@ GpuMemoryBufferFactoryIOSurface::CreateGpuMemoryBuffer(
   {
     base::AutoLock lock(io_surfaces_lock_);
 
-    IOSurfaceMapKey key(id, client_id);
+    IOSurfaceMapKey key(id.id, client_id);
     DCHECK(io_surfaces_.find(key) == io_surfaces_.end());
     io_surfaces_[key] = io_surface;
   }
@@ -181,12 +181,12 @@ void GpuMemoryBufferFactoryIOSurface::DestroyGpuMemoryBuffer(
   {
     base::AutoLock lock(io_surfaces_lock_);
 
-    IOSurfaceMapKey key(id, client_id);
+    IOSurfaceMapKey key(id.id, client_id);
     DCHECK(io_surfaces_.find(key) != io_surfaces_.end());
     io_surfaces_.erase(key);
   }
 
-  IOSurfaceManager::GetInstance()->UnregisterIOSurface(id, client_id);
+  IOSurfaceManager::GetInstance()->UnregisterIOSurface(id.id, client_id);
 }
 
 gpu::ImageFactory* GpuMemoryBufferFactoryIOSurface::AsImageFactory() {
@@ -203,7 +203,7 @@ GpuMemoryBufferFactoryIOSurface::CreateImageForGpuMemoryBuffer(
   base::AutoLock lock(io_surfaces_lock_);
 
   DCHECK_EQ(handle.type, gfx::IO_SURFACE_BUFFER);
-  IOSurfaceMapKey key(handle.id, client_id);
+  IOSurfaceMapKey key(handle.id.id, client_id);
   IOSurfaceMap::iterator it = io_surfaces_.find(key);
   if (it == io_surfaces_.end())
     return scoped_refptr<gfx::GLImage>();
diff --git a/content/common/gpu/gpu_memory_buffer_factory_ozone_native_pixmap.cc b/content/common/gpu/gpu_memory_buffer_factory_ozone_native_pixmap.cc
index 8435d69..6e482e5 100644
--- a/content/common/gpu/gpu_memory_buffer_factory_ozone_native_pixmap.cc
+++ b/content/common/gpu/gpu_memory_buffer_factory_ozone_native_pixmap.cc
@@ -75,7 +75,7 @@ GpuMemoryBufferFactoryOzoneNativePixmap::CreateGpuMemoryBuffer(
     return gfx::GpuMemoryBufferHandle();
   }
   base::AutoLock lock(native_pixmaps_lock_);
-  NativePixmapMapKey key(id, client_id);
+  NativePixmapMapKey key(id.id, client_id);
   DCHECK(native_pixmaps_.find(key) == native_pixmaps_.end())
       << "pixmap with this key must not exist";
   native_pixmaps_[key] = pixmap;
@@ -90,7 +90,7 @@ void GpuMemoryBufferFactoryOzoneNativePixmap::DestroyGpuMemoryBuffer(
     gfx::GpuMemoryBufferId id,
     int client_id) {
   base::AutoLock lock(native_pixmaps_lock_);
-  auto it = native_pixmaps_.find(NativePixmapMapKey(id, client_id));
+  auto it = native_pixmaps_.find(NativePixmapMapKey(id.id, client_id));
   DCHECK(it != native_pixmaps_.end()) << "pixmap with this key must exist";
   native_pixmaps_.erase(it);
 }
@@ -111,7 +111,7 @@ GpuMemoryBufferFactoryOzoneNativePixmap::CreateImageForGpuMemoryBuffer(
   {
     base::AutoLock lock(native_pixmaps_lock_);
     NativePixmapMap::iterator it =
-        native_pixmaps_.find(NativePixmapMapKey(handle.id, client_id));
+        native_pixmaps_.find(NativePixmapMapKey(handle.id.id, client_id));
     if (it == native_pixmaps_.end()) {
       return nullptr;
     }
diff --git a/content/common/gpu/gpu_memory_buffer_factory_surface_texture.cc b/content/common/gpu/gpu_memory_buffer_factory_surface_texture.cc
index 7c3c806..490c45e 100644
--- a/content/common/gpu/gpu_memory_buffer_factory_surface_texture.cc
+++ b/content/common/gpu/gpu_memory_buffer_factory_surface_texture.cc
@@ -61,12 +61,12 @@ GpuMemoryBufferFactorySurfaceTexture::CreateGpuMemoryBuffer(
     return gfx::GpuMemoryBufferHandle();
 
   SurfaceTextureManager::GetInstance()->RegisterSurfaceTexture(
-      id, client_id, surface_texture.get());
+      id.id, client_id, surface_texture.get());
 
   {
     base::AutoLock lock(surface_textures_lock_);
 
-    SurfaceTextureMapKey key(id, client_id);
+    SurfaceTextureMapKey key(id.id, client_id);
     DCHECK(surface_textures_.find(key) == surface_textures_.end());
     surface_textures_[key] = surface_texture;
   }
@@ -83,12 +83,13 @@ void GpuMemoryBufferFactorySurfaceTexture::DestroyGpuMemoryBuffer(
   {
     base::AutoLock lock(surface_textures_lock_);
 
-    SurfaceTextureMapKey key(id, client_id);
+    SurfaceTextureMapKey key(id.id, client_id);
     DCHECK(surface_textures_.find(key) != surface_textures_.end());
     surface_textures_.erase(key);
   }
 
-  SurfaceTextureManager::GetInstance()->UnregisterSurfaceTexture(id, client_id);
+  SurfaceTextureManager::GetInstance()->UnregisterSurfaceTexture(id.id,
+                                                                 client_id);
 }
 
 gpu::ImageFactory* GpuMemoryBufferFactorySurfaceTexture::AsImageFactory() {
@@ -106,7 +107,7 @@ GpuMemoryBufferFactorySurfaceTexture::CreateImageForGpuMemoryBuffer(
 
   DCHECK_EQ(handle.type, gfx::SURFACE_TEXTURE_BUFFER);
 
-  SurfaceTextureMapKey key(handle.id, client_id);
+  SurfaceTextureMapKey key(handle.id.id, client_id);
   SurfaceTextureMap::iterator it = surface_textures_.find(key);
   if (it == surface_textures_.end())
     return scoped_refptr<gfx::GLImage>();
diff --git a/content/common/gpu/gpu_memory_buffer_factory_unittest.cc b/content/common/gpu/gpu_memory_buffer_factory_unittest.cc
index f9dc7e1..dbd9b76 100644
--- a/content/common/gpu/gpu_memory_buffer_factory_unittest.cc
+++ b/content/common/gpu/gpu_memory_buffer_factory_unittest.cc
@@ -28,7 +28,7 @@ class GpuMemoryBufferFactoryTest
 };
 
 TEST_P(GpuMemoryBufferFactoryTest, CreateAndDestroy) {
-  const int kBufferId = 1;
+  const gfx::GpuMemoryBufferId kBufferId(1);
   const int kClientId = 1;
 
   gfx::Size buffer_size(2, 2);
diff --git a/content/common/gpu/gpu_messages.h b/content/common/gpu/gpu_messages.h
index acfbab6..a75b5ad 100644
--- a/content/common/gpu/gpu_messages.h
+++ b/content/common/gpu/gpu_messages.h
@@ -83,7 +83,7 @@ IPC_STRUCT_BEGIN(GPUCreateCommandBufferConfig)
 IPC_STRUCT_END()
 
 IPC_STRUCT_BEGIN(GpuMsg_CreateGpuMemoryBuffer_Params)
-  IPC_STRUCT_MEMBER(int32, id)
+  IPC_STRUCT_MEMBER(gfx::GpuMemoryBufferId, id)
   IPC_STRUCT_MEMBER(gfx::Size, size)
   IPC_STRUCT_MEMBER(gfx::BufferFormat, format)
   IPC_STRUCT_MEMBER(gfx::BufferUsage, usage)
diff --git a/content/content_common.gypi b/content/content_common.gypi
index 15c3889..97590df 100644
--- a/content/content_common.gypi
+++ b/content/content_common.gypi
@@ -272,6 +272,8 @@
       'common/gamepad_param_traits.h',
       'common/gamepad_user_gesture.cc',
       'common/gamepad_user_gesture.h',
+      'common/generic_shared_memory_id_generator.cc',
+      'common/generic_shared_memory_id_generator.h',
       'common/geofencing_messages.h',
       'common/geofencing_types.cc',
       'common/geofencing_types.h',
diff --git a/content/gpu/gpu_child_thread.cc b/content/gpu/gpu_child_thread.cc
index ac79e60..0c00dcc 100644
--- a/content/gpu/gpu_child_thread.cc
+++ b/content/gpu/gpu_child_thread.cc
@@ -80,7 +80,7 @@ class GpuMemoryBufferMessageFilter : public IPC::MessageFilter {
   void OnCreateGpuMemoryBuffer(
       const GpuMsg_CreateGpuMemoryBuffer_Params& params) {
     TRACE_EVENT2("gpu", "GpuMemoryBufferMessageFilter::OnCreateGpuMemoryBuffer",
-                 "id", params.id, "client_id", params.client_id);
+                 "id", params.id.id, "client_id", params.client_id);
     sender_->Send(new GpuHostMsg_GpuMemoryBufferCreated(
         gpu_memory_buffer_factory_->CreateGpuMemoryBuffer(
             params.id, params.size, params.format, params.usage,
@@ -358,4 +358,3 @@ void GpuChildThread::OnGpuSwitched() {
 }
 
 }  // namespace content
-
diff --git a/gpu/command_buffer/tests/gl_manager.cc b/gpu/command_buffer/tests/gl_manager.cc
index 7897d16..f32792f 100644
--- a/gpu/command_buffer/tests/gl_manager.cc
+++ b/gpu/command_buffer/tests/gl_manager.cc
@@ -145,7 +145,7 @@ class GpuMemoryBufferImpl : public gfx::GpuMemoryBuffer {
   }
   gfx::GpuMemoryBufferId GetId() const override {
     NOTREACHED();
-    return 0;
+    return gfx::GpuMemoryBufferId(0);
   }
   gfx::GpuMemoryBufferHandle GetHandle() const override {
     NOTREACHED();
diff --git a/media/renderers/mock_gpu_video_accelerator_factories.cc b/media/renderers/mock_gpu_video_accelerator_factories.cc
index 4fb61ba..58bd5a3 100644
--- a/media/renderers/mock_gpu_video_accelerator_factories.cc
+++ b/media/renderers/mock_gpu_video_accelerator_factories.cc
@@ -32,7 +32,7 @@ class GpuMemoryBufferImpl : public gfx::GpuMemoryBuffer {
   void GetStride(int* stride) const override { stride[0] = size_.width(); }
   gfx::GpuMemoryBufferId GetId() const override {
     NOTREACHED();
-    return 0;
+    return gfx::GpuMemoryBufferId(0);
   }
   gfx::GpuMemoryBufferHandle GetHandle() const override {
     NOTREACHED();
diff --git a/ui/gfx/BUILD.gn b/ui/gfx/BUILD.gn
index 4cd3576..32fc674 100644
--- a/ui/gfx/BUILD.gn
+++ b/ui/gfx/BUILD.gn
@@ -103,6 +103,8 @@ component("gfx") {
     "font_render_params_win.cc",
     "gdi_util.cc",
     "gdi_util.h",
+    "generic_shared_memory_id.cc",
+    "generic_shared_memory_id.h",
     "gfx_paths.cc",
     "gfx_paths.h",
     "gpu_memory_buffer.cc",
diff --git a/ui/gfx/generic_shared_memory_id.cc b/ui/gfx/generic_shared_memory_id.cc
new file mode 100644
index 0000000..33a5ef0
--- /dev/null
+++ b/ui/gfx/generic_shared_memory_id.cc
@@ -0,0 +1,20 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/gfx/generic_shared_memory_id.h"
+
+#include "base/format_macros.h"
+#include "base/strings/stringprintf.h"
+
+namespace gfx {
+
+base::trace_event::MemoryAllocatorDumpGuid GetGenericSharedMemoryGUIDForTracing(
+    uint64_t tracing_process_id,
+    GenericSharedMemoryId generic_shared_memory_id) {
+  return base::trace_event::MemoryAllocatorDumpGuid(
+      base::StringPrintf("genericsharedmemory-x-process/%" PRIx64 "/%d",
+                         tracing_process_id, generic_shared_memory_id.id));
+}
+
+}  // namespace gfx
diff --git a/ui/gfx/generic_shared_memory_id.h b/ui/gfx/generic_shared_memory_id.h
new file mode 100644
index 0000000..9aa226f
--- /dev/null
+++ b/ui/gfx/generic_shared_memory_id.h
@@ -0,0 +1,54 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_GFX_GENERIC_SHARED_MEMORY_ID_H_
+#define UI_GFX_GENERIC_SHARED_MEMORY_ID_H_
+
+#include "base/trace_event/memory_allocator_dump.h"
+#include "ui/gfx/gfx_export.h"
+
+namespace gfx {
+
+// Defines an ID type which is used across all types of shared memory
+// allocations in content/. This ID type is in ui/gfx, as components outside
+// content/ may need to hold an ID (but should not generate one).
+class GFX_EXPORT GenericSharedMemoryId {
+ public:
+  int id;
+
+  // Invalid ID is -1 to match semantics of base::StaticAtomicSequenceNumber.
+  GenericSharedMemoryId() : id(-1) {}
+  explicit GenericSharedMemoryId(int id) : id(id) {}
+  GenericSharedMemoryId(const GenericSharedMemoryId& other) = default;
+  GenericSharedMemoryId& operator=(const GenericSharedMemoryId& other) =
+      default;
+
+  bool operator==(const GenericSharedMemoryId& other) const {
+    return id == other.id;
+  }
+
+  bool operator<(const GenericSharedMemoryId& other) const {
+    return id < other.id;
+  }
+};
+
+// Generates GUID which can be used to trace shared memory using its
+// GenericSharedMemoryId.
+GFX_EXPORT base::trace_event::MemoryAllocatorDumpGuid
+GetGenericSharedMemoryGUIDForTracing(
+    uint64_t tracing_process_id,
+    GenericSharedMemoryId generic_shared_memory_id);
+
+}  // namespace gfx
+
+namespace BASE_HASH_NAMESPACE {
+template <>
+struct hash<gfx::GenericSharedMemoryId> {
+  size_t operator()(gfx::GenericSharedMemoryId key) const {
+    return BASE_HASH_NAMESPACE::hash<int>()(key.id);
+  }
+};
+}  // namespace BASE_HASH_NAMESPACE
+
+#endif  // UI_GFX_GENERIC_SHARED_MEMORY_ID_H_
diff --git a/ui/gfx/gfx.gyp b/ui/gfx/gfx.gyp
index d741b0e..98575ae 100644
--- a/ui/gfx/gfx.gyp
+++ b/ui/gfx/gfx.gyp
@@ -173,6 +173,8 @@
         'font_render_params_linux.cc',
         'font_render_params_mac.cc',
         'font_render_params_win.cc',
+        'generic_shared_memory_id.cc',
+        'generic_shared_memory_id.h',
         'gfx_export.h',
         'gfx_paths.cc',
         'gfx_paths.h',
diff --git a/ui/gfx/gpu_memory_buffer.cc b/ui/gfx/gpu_memory_buffer.cc
index 44fcd31..9ccd410 100644
--- a/ui/gfx/gpu_memory_buffer.cc
+++ b/ui/gfx/gpu_memory_buffer.cc
@@ -4,17 +4,16 @@
 
 #include "ui/gfx/gpu_memory_buffer.h"
 
-#include "base/format_macros.h"
-#include "base/strings/stringprintf.h"
-
 namespace gfx {
 
 base::trace_event::MemoryAllocatorDumpGuid GetGpuMemoryBufferGUIDForTracing(
     uint64 tracing_process_id,
     GpuMemoryBufferId buffer_id) {
-  return base::trace_event::MemoryAllocatorDumpGuid(
-      base::StringPrintf("gpumemorybuffer-x-process/%" PRIx64 "/%d",
-                         tracing_process_id, buffer_id));
+  // TODO(ericrk): Currently this function just wraps
+  // GetGenericSharedMemoryGUIDForTracing, we may want to special case this if
+  // the GPU memory buffer is not backed by shared memory.
+  return gfx::GetGenericSharedMemoryGUIDForTracing(tracing_process_id,
+                                                   buffer_id);
 }
 
 GpuMemoryBufferHandle::GpuMemoryBufferHandle()
diff --git a/ui/gfx/gpu_memory_buffer.h b/ui/gfx/gpu_memory_buffer.h
index 263a0ef..1234dc2 100644
--- a/ui/gfx/gpu_memory_buffer.h
+++ b/ui/gfx/gpu_memory_buffer.h
@@ -9,6 +9,7 @@
 #include "base/trace_event/memory_dump_manager.h"
 #include "build/build_config.h"
 #include "ui/gfx/buffer_types.h"
+#include "ui/gfx/generic_shared_memory_id.h"
 #include "ui/gfx/gfx_export.h"
 
 extern "C" typedef struct _ClientBuffer* ClientBuffer;
@@ -24,7 +25,7 @@ enum GpuMemoryBufferType {
   GPU_MEMORY_BUFFER_TYPE_LAST = OZONE_NATIVE_PIXMAP
 };
 
-using GpuMemoryBufferId = int32;
+using GpuMemoryBufferId = gfx::GenericSharedMemoryId;
 
 struct GFX_EXPORT GpuMemoryBufferHandle {
   GpuMemoryBufferHandle();