Revert 251207 "Use gpu::Mailbox instead of std:string in IPCs"

Speculative revert to determine whether it is causing the below
WebViewTest.AutoSizeSW failure on the Linux Test bots (e.g.,
http://build.chromium.org/p/chromium.linux/builders/Linux%20Tests%20%28dbg%29%281%29/builds/30888/steps/browser_tests/logs/AutoSizeSW):

FATAL:texture_layer.cc(141)] Check failed: !mailbox.IsValid() || !holder_ref_
|| !mailbox.Equals(holder_ref_->holder()->mailbox()).

This failure also appeared on the trybot run for this CL.

> Use gpu::Mailbox instead of std:string in IPCs
> 
> - easier to read
> - safer since gpu::Mailbox is constant size and checked in the ParamTraits
> 
> BUG=None
> 
> Review URL: https://codereview.chromium.org/148003006

TBR=piman@chromium.org

Review URL: https://codereview.chromium.org/163433008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251281 0039d316-1c4b-4281-b951-d872f2087c98

24 files changed, 90 insertions, 83 deletions

diff --git a/content/browser/browser_plugin/browser_plugin_guest.cc b/content/browser/browser_plugin/browser_plugin_guest.cc
index 68db4d9..9e8e517 100644
--- a/content/browser/browser_plugin/browser_plugin_guest.cc
+++ b/content/browser/browser_plugin/browser_plugin_guest.cc
@@ -1157,10 +1157,10 @@ void BrowserPluginGuest::RenderProcessGone(base::TerminationStatus status) {
 void BrowserPluginGuest::AcknowledgeBufferPresent(
     int route_id,
     int gpu_host_id,
-    const gpu::Mailbox& mailbox,
+    const std::string& mailbox_name,
     uint32 sync_point) {
   AcceleratedSurfaceMsg_BufferPresented_Params ack_params;
-  ack_params.mailbox = mailbox;
+  ack_params.mailbox_name = mailbox_name;
   ack_params.sync_point = sync_point;
   RenderWidgetHostImpl::AcknowledgeBufferPresent(route_id,
                                                  gpu_host_id,
@@ -1610,7 +1610,7 @@ void BrowserPluginGuest::OnSwapBuffersACK(
     int instance_id,
     const FrameHostMsg_BuffersSwappedACK_Params& params) {
   AcknowledgeBufferPresent(params.gpu_route_id, params.gpu_host_id,
-                           params.mailbox, params.sync_point);
+                           params.mailbox_name, params.sync_point);
 
 // This is only relevant on MACOSX and WIN when threaded compositing
 // is not enabled. In threaded mode, above ACK is sufficient.
diff --git a/content/browser/browser_plugin/browser_plugin_guest.h b/content/browser/browser_plugin/browser_plugin_guest.h
index 870783c..a986bdb 100644
--- a/content/browser/browser_plugin/browser_plugin_guest.h
+++ b/content/browser/browser_plugin/browser_plugin_guest.h
@@ -67,10 +67,6 @@ namespace gfx {
 class Range;
 }
 
-namespace gpu {
-struct Mailbox;
-}
-
 namespace content {
 
 class BrowserPluginHostFactory;
@@ -290,7 +286,7 @@ class CONTENT_EXPORT BrowserPluginGuest
   // BrowserPluginGuest is already destroyed.
   static void AcknowledgeBufferPresent(int route_id,
                                        int gpu_host_id,
-                                       const gpu::Mailbox& mailbox,
+                                       const std::string& mailbox_name,
                                        uint32 sync_point);
 
   // Returns whether BrowserPluginGuest is interested in receiving the given
diff --git a/content/browser/browser_plugin/browser_plugin_guest_manager.cc b/content/browser/browser_plugin/browser_plugin_guest_manager.cc
index 4ef9e29..405a233 100644
--- a/content/browser/browser_plugin/browser_plugin_guest_manager.cc
+++ b/content/browser/browser_plugin/browser_plugin_guest_manager.cc
@@ -221,7 +221,7 @@ void BrowserPluginGuestManager::OnUnhandledSwapBuffersACK(
     const FrameHostMsg_BuffersSwappedACK_Params& params) {
   BrowserPluginGuest::AcknowledgeBufferPresent(params.gpu_route_id,
                                                params.gpu_host_id,
-                                               params.mailbox,
+                                               params.mailbox_name,
                                                params.sync_point);
 }
 
diff --git a/content/browser/compositor/gpu_process_transport_factory.cc b/content/browser/compositor/gpu_process_transport_factory.cc
index 6724060..d72958b 100644
--- a/content/browser/compositor/gpu_process_transport_factory.cc
+++ b/content/browser/compositor/gpu_process_transport_factory.cc
@@ -29,7 +29,6 @@
 #include "content/common/gpu/gpu_process_launch_causes.h"
 #include "gpu/GLES2/gl2extchromium.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
-#include "gpu/command_buffer/common/mailbox.h"
 #include "third_party/khronos/GLES2/gl2.h"
 #include "ui/compositor/compositor.h"
 #include "ui/compositor/compositor_constants.h"
@@ -114,27 +113,29 @@ class ImageTransportClientTexture : public OwnedTexture {
                      device_scale_factor,
                      texture_id) {}
 
-  virtual void Consume(const gpu::Mailbox& mailbox,
+  virtual void Consume(const std::string& mailbox_name,
                        const gfx::Size& new_size) OVERRIDE {
-    mailbox_ = mailbox;
-    if (mailbox.IsZero())
+    DCHECK(mailbox_name.size() == GL_MAILBOX_SIZE_CHROMIUM);
+    mailbox_name_ = mailbox_name;
+    if (mailbox_name.empty())
       return;
 
     DCHECK(provider_ && texture_id_);
     GLES2Interface* gl = provider_->ContextGL();
     gl->BindTexture(GL_TEXTURE_2D, texture_id_);
-    gl->ConsumeTextureCHROMIUM(GL_TEXTURE_2D, mailbox.name);
+    gl->ConsumeTextureCHROMIUM(
+        GL_TEXTURE_2D, reinterpret_cast<const GLbyte*>(mailbox_name.c_str()));
     size_ = new_size;
     gl->ShallowFlushCHROMIUM();
   }
 
-  virtual gpu::Mailbox Produce() OVERRIDE { return mailbox_; }
+  virtual std::string Produce() OVERRIDE { return mailbox_name_; }
 
  protected:
   virtual ~ImageTransportClientTexture() {}
 
  private:
-  gpu::Mailbox mailbox_;
+  std::string mailbox_name_;
   DISALLOW_COPY_AND_ASSIGN(ImageTransportClientTexture);
 };
 
diff --git a/content/browser/compositor/no_transport_image_transport_factory.cc b/content/browser/compositor/no_transport_image_transport_factory.cc
index d67be0c..f278e49 100644
--- a/content/browser/compositor/no_transport_image_transport_factory.cc
+++ b/content/browser/compositor/no_transport_image_transport_factory.cc
@@ -25,7 +25,7 @@ class FakeTexture : public ui::Texture {
 
   virtual unsigned int PrepareTexture() OVERRIDE { return texture_; }
 
-  virtual void Consume(const gpu::Mailbox& mailbox,
+  virtual void Consume(const std::string& mailbox_name,
                        const gfx::Size& new_size) OVERRIDE {
     size_ = new_size;
   }
diff --git a/content/browser/frame_host/cross_process_frame_connector.cc b/content/browser/frame_host/cross_process_frame_connector.cc
index 0378181..f386df8 100644
--- a/content/browser/frame_host/cross_process_frame_connector.cc
+++ b/content/browser/frame_host/cross_process_frame_connector.cc
@@ -67,7 +67,7 @@ void CrossProcessFrameConnector::ChildFrameBuffersSwapped(
 
   FrameMsg_BuffersSwapped_Params params;
   params.size = gpu_params.size;
-  params.mailbox = gpu_params.mailbox;
+  params.mailbox_name = gpu_params.mailbox_name;
   params.gpu_route_id = gpu_params.route_id;
   params.gpu_host_id = gpu_host_id;
 
@@ -94,7 +94,7 @@ void CrossProcessFrameConnector::ChildFrameCompositorFrameSwapped(
 void CrossProcessFrameConnector::OnBuffersSwappedACK(
     const FrameHostMsg_BuffersSwappedACK_Params& params) {
   AcceleratedSurfaceMsg_BufferPresented_Params ack_params;
-  ack_params.mailbox = params.mailbox;
+  ack_params.mailbox_name = params.mailbox_name;
   ack_params.sync_point = params.sync_point;
   RenderWidgetHostImpl::AcknowledgeBufferPresent(params.gpu_route_id,
                                                  params.gpu_host_id,
diff --git a/content/browser/frame_host/render_widget_host_view_guest.cc b/content/browser/frame_host/render_widget_host_view_guest.cc
index eef781b..0e26c92 100644
--- a/content/browser/frame_host/render_widget_host_view_guest.cc
+++ b/content/browser/frame_host/render_widget_host_view_guest.cc
@@ -170,7 +170,7 @@ void RenderWidgetHostViewGuest::AcceleratedSurfaceBuffersSwapped(
   guest_->clear_damage_buffer();
   FrameMsg_BuffersSwapped_Params guest_params;
   guest_params.size = params.size;
-  guest_params.mailbox = params.mailbox;
+  guest_params.mailbox_name = params.mailbox_name;
   guest_params.gpu_route_id = params.route_id;
   guest_params.gpu_host_id = gpu_host_id;
   guest_->SendMessageToEmbedder(
diff --git a/content/browser/gpu/gpu_process_host_ui_shim.cc b/content/browser/gpu/gpu_process_host_ui_shim.cc
index ec62dff..4d46484 100644
--- a/content/browser/gpu/gpu_process_host_ui_shim.cc
+++ b/content/browser/gpu/gpu_process_host_ui_shim.cc
@@ -288,13 +288,17 @@ void GpuProcessHostUIShim::OnAcceleratedSurfaceBuffersSwapped(
                                "GpuHostMsg_AcceleratedSurfaceBuffersSwapped"))
     return;
   AcceleratedSurfaceMsg_BufferPresented_Params ack_params;
-  ack_params.mailbox = params.mailbox;
+  ack_params.mailbox_name = params.mailbox_name;
   ack_params.sync_point = 0;
   ScopedSendOnIOThread delayed_send(
       host_id_,
       new AcceleratedSurfaceMsg_BufferPresented(params.route_id,
                                                 ack_params));
 
+  if (!params.mailbox_name.empty() &&
+      params.mailbox_name.length() != GL_MAILBOX_SIZE_CHROMIUM)
+    return;
+
   RenderWidgetHostViewPort* view = GetRenderWidgetHostViewFromSurfaceID(
       params.surface_id);
   if (!view)
@@ -334,13 +338,17 @@ void GpuProcessHostUIShim::OnAcceleratedSurfacePostSubBuffer(
                                "GpuHostMsg_AcceleratedSurfacePostSubBuffer"))
     return;
   AcceleratedSurfaceMsg_BufferPresented_Params ack_params;
-  ack_params.mailbox = params.mailbox;
+  ack_params.mailbox_name = params.mailbox_name;
   ack_params.sync_point = 0;
   ScopedSendOnIOThread delayed_send(
       host_id_,
       new AcceleratedSurfaceMsg_BufferPresented(params.route_id,
                                                 ack_params));
 
+  if (!params.mailbox_name.empty() &&
+      params.mailbox_name.length() != GL_MAILBOX_SIZE_CHROMIUM)
+    return;
+
   RenderWidgetHostViewPort* view =
       GetRenderWidgetHostViewFromSurfaceID(params.surface_id);
   if (!view)
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index 2a926bc..81245e5 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -327,7 +327,10 @@ void SendCompositorFrameAck(
   DCHECK(!texture_to_produce.get() || !skip_frame);
   if (texture_to_produce.get()) {
     GLHelper* gl_helper = ImageTransportFactory::GetInstance()->GetGLHelper();
-    ack.gl_frame_data->mailbox = texture_to_produce->Produce();
+    std::string mailbox_name = texture_to_produce->Produce();
+    std::copy(mailbox_name.data(),
+              mailbox_name.data() + mailbox_name.length(),
+              reinterpret_cast<char*>(ack.gl_frame_data->mailbox.name));
     ack.gl_frame_data->size = texture_to_produce->size();
     ack.gl_frame_data->sync_point =
         gl_helper ? gl_helper->InsertSyncPoint() : 0;
@@ -345,7 +348,7 @@ void SendCompositorFrameAck(
 void AcknowledgeBufferForGpu(
     int32 route_id,
     int gpu_host_id,
-    const gpu::Mailbox& received_mailbox,
+    const std::string& received_mailbox,
     bool skip_frame,
     const scoped_refptr<ui::Texture>& texture_to_produce) {
   AcceleratedSurfaceMsg_BufferPresented_Params ack;
@@ -353,10 +356,10 @@ void AcknowledgeBufferForGpu(
   DCHECK(!texture_to_produce.get() || !skip_frame);
   if (texture_to_produce.get()) {
     GLHelper* gl_helper = ImageTransportFactory::GetInstance()->GetGLHelper();
-    ack.mailbox = texture_to_produce->Produce();
+    ack.mailbox_name = texture_to_produce->Produce();
     sync_point = gl_helper ? gl_helper->InsertSyncPoint() : 0;
   } else if (skip_frame) {
-    ack.mailbox = received_mailbox;
+    ack.mailbox_name = received_mailbox;
     ack.sync_point = 0;
   }
 
@@ -1299,7 +1302,7 @@ bool RenderWidgetHostViewAura::SwapBuffersPrepare(
     const gfx::Rect& surface_rect,
     float surface_scale_factor,
     const gfx::Rect& damage_rect,
-    const gpu::Mailbox& mailbox,
+    const std::string& mailbox_name,
     const BufferPresentedCallback& ack_callback) {
   if (last_swapped_surface_size_ != surface_rect.size()) {
     // The surface could have shrunk since we skipped an update, in which
@@ -1312,7 +1315,7 @@ bool RenderWidgetHostViewAura::SwapBuffersPrepare(
 
   if (ShouldSkipFrame(ConvertSizeToDIP(surface_scale_factor,
                                        surface_rect.size())) ||
-      mailbox.IsZero()) {
+      mailbox_name.empty()) {
     skipped_damage_.op(RectToSkIRect(damage_rect), SkRegion::kUnion_Op);
     ack_callback.Run(true, scoped_refptr<ui::Texture>());
     return false;
@@ -1327,7 +1330,7 @@ bool RenderWidgetHostViewAura::SwapBuffersPrepare(
     return false;
   }
 
-  current_surface_->Consume(mailbox, surface_rect.size());
+  current_surface_->Consume(mailbox_name, surface_rect.size());
   released_front_lock_ = NULL;
   UpdateExternalTexture();
 
@@ -1393,11 +1396,11 @@ void RenderWidgetHostViewAura::AcceleratedSurfaceBuffersSwapped(
       &AcknowledgeBufferForGpu,
       params_in_pixel.route_id,
       gpu_host_id,
-      params_in_pixel.mailbox);
+      params_in_pixel.mailbox_name);
   BuffersSwapped(params_in_pixel.size,
                  gfx::Rect(params_in_pixel.size),
                  params_in_pixel.scale_factor,
-                 params_in_pixel.mailbox,
+                 params_in_pixel.mailbox_name,
                  params_in_pixel.latency_info,
                  ack_callback);
 }
@@ -1688,10 +1691,13 @@ void RenderWidgetHostViewAura::OnSwapCompositorFrame(
   GLHelper* gl_helper = ImageTransportFactory::GetInstance()->GetGLHelper();
   gl_helper->WaitSyncPoint(frame->gl_frame_data->sync_point);
 
+  std::string mailbox_name(
+      reinterpret_cast<const char*>(frame->gl_frame_data->mailbox.name),
+      sizeof(frame->gl_frame_data->mailbox.name));
   BuffersSwapped(frame->gl_frame_data->size,
                  frame->gl_frame_data->sub_buffer_rect,
                  frame->metadata.device_scale_factor,
-                 frame->gl_frame_data->mailbox,
+                 mailbox_name,
                  frame->metadata.latency_info,
                  ack_callback);
 }
@@ -1719,7 +1725,7 @@ void RenderWidgetHostViewAura::BuffersSwapped(
     const gfx::Size& surface_size,
     const gfx::Rect& damage_rect,
     float surface_scale_factor,
-    const gpu::Mailbox& mailbox,
+    const std::string& mailbox_name,
     const std::vector<ui::LatencyInfo>& latency_info,
     const BufferPresentedCallback& ack_callback) {
   scoped_refptr<ui::Texture> previous_texture(current_surface_);
@@ -1729,7 +1735,7 @@ void RenderWidgetHostViewAura::BuffersSwapped(
   if (!SwapBuffersPrepare(surface_rect,
                           surface_scale_factor,
                           damage_rect,
-                          mailbox,
+                          mailbox_name,
                           ack_callback)) {
     return;
   }
@@ -1796,11 +1802,11 @@ void RenderWidgetHostViewAura::AcceleratedSurfacePostSubBuffer(
       base::Bind(&AcknowledgeBufferForGpu,
                  params_in_pixel.route_id,
                  gpu_host_id,
-                 params_in_pixel.mailbox);
+                 params_in_pixel.mailbox_name);
   BuffersSwapped(params_in_pixel.surface_size,
                  damage_rect,
                  params_in_pixel.surface_scale_factor,
-                 params_in_pixel.mailbox,
+                 params_in_pixel.mailbox_name,
                  params_in_pixel.latency_info,
                  ack_callback);
 }
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.h b/content/browser/renderer_host/render_widget_host_view_aura.h
index 0e01067..3c3757d 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.h
+++ b/content/browser/renderer_host/render_widget_host_view_aura.h
@@ -60,10 +60,6 @@ class Canvas;
 class Display;
 }
 
-namespace gpu {
-struct Mailbox;
-}
-
 namespace ui {
 class CompositorLock;
 class CompositorVSyncManager;
@@ -534,14 +530,14 @@ class CONTENT_EXPORT RenderWidgetHostViewAura
   void BuffersSwapped(const gfx::Size& surface_size,
                       const gfx::Rect& damage_rect,
                       float surface_scale_factor,
-                      const gpu::Mailbox& mailbox,
+                      const std::string& mailbox_name,
                       const std::vector<ui::LatencyInfo>& latency_info,
                       const BufferPresentedCallback& ack_callback);
 
   bool SwapBuffersPrepare(const gfx::Rect& surface_rect,
                           float surface_scale_factor,
                           const gfx::Rect& damage_rect,
-                          const gpu::Mailbox& mailbox,
+                          const std::string& mailbox_name,
                           const BufferPresentedCallback& ack_callback);
 
   void SwapBuffersCompleted(
diff --git a/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc b/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc
index cd5cb3f..6911f28 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc
@@ -949,7 +949,7 @@ TEST_F(RenderWidgetHostViewAuraTest, SwapNotifiesWindow) {
   GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params params;
   params.surface_id = widget_host_->surface_id();
   params.route_id = widget_host_->GetRoutingID();
-  memset(params.mailbox.name, '1', sizeof(params.mailbox.name));
+  params.mailbox_name = std::string(64, '1');
   params.size = view_size;
   params.scale_factor = 1.f;
 
@@ -968,7 +968,7 @@ TEST_F(RenderWidgetHostViewAuraTest, SwapNotifiesWindow) {
   GpuHostMsg_AcceleratedSurfacePostSubBuffer_Params post_params;
   post_params.surface_id = widget_host_->surface_id();
   post_params.route_id = widget_host_->GetRoutingID();
-  memset(post_params.mailbox.name, '1', sizeof(post_params.mailbox.name));
+  post_params.mailbox_name = std::string(64, '1');
   post_params.surface_size = gfx::Size(200, 200);
   post_params.surface_scale_factor = 2.f;
   post_params.x = 40;
diff --git a/content/common/frame_param_macros.h b/content/common/frame_param_macros.h
index 3f37975..2cd44e7 100644
--- a/content/common/frame_param_macros.h
+++ b/content/common/frame_param_macros.h
@@ -24,7 +24,7 @@
 IPC_STRUCT_BEGIN(FrameMsg_BuffersSwapped_Params)
   IPC_STRUCT_MEMBER(int, gpu_host_id)
   IPC_STRUCT_MEMBER(int, gpu_route_id)
-  IPC_STRUCT_MEMBER(gpu::Mailbox, mailbox)
+  IPC_STRUCT_MEMBER(std::string, mailbox_name)
   IPC_STRUCT_MEMBER(gfx::Size, size)
 IPC_STRUCT_END()
 
@@ -40,7 +40,7 @@ IPC_STRUCT_END()
 IPC_STRUCT_BEGIN(FrameHostMsg_BuffersSwappedACK_Params)
   IPC_STRUCT_MEMBER(int, gpu_host_id)
   IPC_STRUCT_MEMBER(int, gpu_route_id)
-  IPC_STRUCT_MEMBER(gpu::Mailbox, mailbox)
+  IPC_STRUCT_MEMBER(std::string, mailbox_name)
   IPC_STRUCT_MEMBER(uint32, sync_point)
 IPC_STRUCT_END()
 
diff --git a/content/common/gpu/gpu_messages.h b/content/common/gpu/gpu_messages.h
index 2db1a1d..7754ec3 100644
--- a/content/common/gpu/gpu_messages.h
+++ b/content/common/gpu/gpu_messages.h
@@ -70,7 +70,7 @@ IPC_STRUCT_BEGIN(GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params)
   IPC_STRUCT_MEMBER(int32, surface_id)
   IPC_STRUCT_MEMBER(uint64, surface_handle)
   IPC_STRUCT_MEMBER(int32, route_id)
-  IPC_STRUCT_MEMBER(gpu::Mailbox, mailbox)
+  IPC_STRUCT_MEMBER(std::string, mailbox_name)
   IPC_STRUCT_MEMBER(gfx::Size, size)
   IPC_STRUCT_MEMBER(float, scale_factor)
   IPC_STRUCT_MEMBER(std::vector<ui::LatencyInfo>, latency_info)
@@ -84,7 +84,7 @@ IPC_STRUCT_BEGIN(GpuHostMsg_AcceleratedSurfacePostSubBuffer_Params)
   IPC_STRUCT_MEMBER(int, y)
   IPC_STRUCT_MEMBER(int, width)
   IPC_STRUCT_MEMBER(int, height)
-  IPC_STRUCT_MEMBER(gpu::Mailbox, mailbox)
+  IPC_STRUCT_MEMBER(std::string, mailbox_name)
   IPC_STRUCT_MEMBER(gfx::Size, surface_size)
   IPC_STRUCT_MEMBER(float, surface_scale_factor)
   IPC_STRUCT_MEMBER(std::vector<ui::LatencyInfo>, latency_info)
@@ -95,7 +95,7 @@ IPC_STRUCT_BEGIN(GpuHostMsg_AcceleratedSurfaceRelease_Params)
 IPC_STRUCT_END()
 
 IPC_STRUCT_BEGIN(AcceleratedSurfaceMsg_BufferPresented_Params)
-  IPC_STRUCT_MEMBER(gpu::Mailbox, mailbox)
+  IPC_STRUCT_MEMBER(std::string, mailbox_name)
   IPC_STRUCT_MEMBER(uint32, sync_point)
 #if defined(OS_MACOSX)
   IPC_STRUCT_MEMBER(int32, renderer_id)
diff --git a/content/common/gpu/texture_image_transport_surface.cc b/content/common/gpu/texture_image_transport_surface.cc
index 30a54fb..f13a986 100644
--- a/content/common/gpu/texture_image_transport_surface.cc
+++ b/content/common/gpu/texture_image_transport_surface.cc
@@ -218,7 +218,9 @@ bool TextureImageTransportSurface::SwapBuffers() {
   GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params params;
   params.size = backbuffer_size();
   params.scale_factor = scale_factor_;
-  params.mailbox = back_mailbox_;
+  params.mailbox_name.assign(
+      reinterpret_cast<const char*>(&back_mailbox_),
+      sizeof(back_mailbox_));
 
   glFlush();
 
@@ -256,7 +258,9 @@ bool TextureImageTransportSurface::PostSubBuffer(
   params.y = y;
   params.width = width;
   params.height = height;
-  params.mailbox = back_mailbox_;
+  params.mailbox_name.assign(
+      reinterpret_cast<const char*>(&back_mailbox_),
+      sizeof(back_mailbox_));
 
   glFlush();
 
@@ -290,17 +294,18 @@ unsigned TextureImageTransportSurface::GetFormat() {
 void TextureImageTransportSurface::OnBufferPresented(
     const AcceleratedSurfaceMsg_BufferPresented_Params& params) {
   if (params.sync_point == 0) {
-    BufferPresentedImpl(params.mailbox);
+    BufferPresentedImpl(params.mailbox_name);
   } else {
     helper_->manager()->sync_point_manager()->AddSyncPointCallback(
         params.sync_point,
         base::Bind(&TextureImageTransportSurface::BufferPresentedImpl,
                    this,
-                   params.mailbox));
+                   params.mailbox_name));
   }
 }
 
-void TextureImageTransportSurface::BufferPresentedImpl(const Mailbox& mailbox) {
+void TextureImageTransportSurface::BufferPresentedImpl(
+    const std::string& mailbox_name) {
   DCHECK(is_swap_buffers_pending_);
   is_swap_buffers_pending_ = false;
 
@@ -316,8 +321,11 @@ void TextureImageTransportSurface::BufferPresentedImpl(const Mailbox& mailbox) {
   DCHECK(backbuffer_.get());
 
   bool swap = true;
-  if (!mailbox.IsZero()) {
-    if (mailbox != back_mailbox_) {
+  if (!mailbox_name.empty()) {
+    DCHECK(mailbox_name.length() == GL_MAILBOX_SIZE_CHROMIUM);
+    if (!memcmp(mailbox_name.data(),
+                &back_mailbox_,
+                mailbox_name.length())) {
       // The browser has skipped the frame to unblock the GPU process, waiting
       // for one of the right size, and returned the back buffer, so don't swap.
       swap = false;
diff --git a/content/common/gpu/texture_image_transport_surface.h b/content/common/gpu/texture_image_transport_surface.h
index a86ff27..ab3eb44 100644
--- a/content/common/gpu/texture_image_transport_surface.h
+++ b/content/common/gpu/texture_image_transport_surface.h
@@ -74,7 +74,7 @@ class TextureImageTransportSurface
   void AttachBackTextureToFBO();
   void ReleaseBackTexture();
   void ReleaseFrontTexture();
-  void BufferPresentedImpl(const gpu::Mailbox& mailbox_name);
+  void BufferPresentedImpl(const std::string& mailbox_name);
 
   // The framebuffer that represents this surface (service id). Allocated lazily
   // in OnMakeCurrent.
diff --git a/content/renderer/browser_plugin/browser_plugin.cc b/content/renderer/browser_plugin/browser_plugin.cc
index 3d20a6e..974c3b0 100644
--- a/content/renderer/browser_plugin/browser_plugin.cc
+++ b/content/renderer/browser_plugin/browser_plugin.cc
@@ -437,7 +437,7 @@ void BrowserPlugin::OnBuffersSwapped(
   EnableCompositing(true);
 
   compositing_helper_->OnBuffersSwapped(params.size,
-                                        params.mailbox,
+                                        params.mailbox_name,
                                         params.gpu_route_id,
                                         params.gpu_host_id,
                                         GetDeviceScaleFactor());
diff --git a/content/renderer/child_frame_compositing_helper.cc b/content/renderer/child_frame_compositing_helper.cc
index cc3bc50..15cf383 100644
--- a/content/renderer/child_frame_compositing_helper.cc
+++ b/content/renderer/child_frame_compositing_helper.cc
@@ -246,10 +246,12 @@ void ChildFrameCompositingHelper::MailboxReleased(SwapBuffersInfo mailbox,
   ack_pending_ = false;
   switch (mailbox.type) {
     case TEXTURE_IMAGE_TRANSPORT: {
+      std::string mailbox_name(reinterpret_cast<const char*>(mailbox.name.name),
+                               sizeof(mailbox.name.name));
       FrameHostMsg_BuffersSwappedACK_Params params;
       params.gpu_host_id = mailbox.host_id;
       params.gpu_route_id = mailbox.route_id;
-      params.mailbox = mailbox.name;
+      params.mailbox_name = mailbox_name;
       params.sync_point = sync_point;
       SendBuffersSwappedACKToBrowser(params);
       break;
@@ -376,12 +378,12 @@ void ChildFrameCompositingHelper::OnBuffersSwappedPrivate(
 
 void ChildFrameCompositingHelper::OnBuffersSwapped(
     const gfx::Size& size,
-    const gpu::Mailbox& mailbox,
+    const std::string& mailbox_name,
     int gpu_route_id,
     int gpu_host_id,
     float device_scale_factor) {
   SwapBuffersInfo swap_info;
-  swap_info.name = mailbox;
+  swap_info.name.SetName(reinterpret_cast<const int8*>(mailbox_name.data()));
   swap_info.type = TEXTURE_IMAGE_TRANSPORT;
   swap_info.size = size;
   swap_info.route_id = gpu_route_id;
diff --git a/content/renderer/child_frame_compositing_helper.h b/content/renderer/child_frame_compositing_helper.h
index 1ec0585..686d9a2 100644
--- a/content/renderer/child_frame_compositing_helper.h
+++ b/content/renderer/child_frame_compositing_helper.h
@@ -69,7 +69,7 @@ class CONTENT_EXPORT ChildFrameCompositingHelper
   void EnableCompositing(bool);
   void OnContainerDestroy();
   void OnBuffersSwapped(const gfx::Size& size,
-                        const gpu::Mailbox& mailbox,
+                        const std::string& mailbox_name,
                         int gpu_route_id,
                         int gpu_host_id,
                         float device_scale_factor);
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index af5e0d5..1b13f68 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -487,7 +487,7 @@ void RenderFrameImpl::OnBuffersSwapped(
   }
   compositing_helper_->OnBuffersSwapped(
       params.size,
-      params.mailbox,
+      params.mailbox_name,
       params.gpu_route_id,
       params.gpu_host_id,
       render_view_->GetWebView()->deviceScaleFactor());
diff --git a/gpu/command_buffer/common/mailbox.h b/gpu/command_buffer/common/mailbox.h
index d9d25d4..938167f 100644
--- a/gpu/command_buffer/common/mailbox.h
+++ b/gpu/command_buffer/common/mailbox.h
@@ -21,12 +21,6 @@ struct GPU_EXPORT Mailbox {
   bool operator<(const Mailbox& other) const {
     return memcmp(this, &other, sizeof other) < 0;
   }
-  bool operator==(const Mailbox& other) const {
-    return memcmp(this, &other, sizeof other) == 0;
-  }
-  bool operator!=(const Mailbox& other) const {
-    return !operator==(other);
-  }
 };
 
 }  // namespace gpu
diff --git a/gpu/command_buffer/service/mailbox_manager.h b/gpu/command_buffer/service/mailbox_manager.h
index 01b74b2..e06ef2d 100644
--- a/gpu/command_buffer/service/mailbox_manager.h
+++ b/gpu/command_buffer/service/mailbox_manager.h
@@ -64,11 +64,11 @@ class GPU_EXPORT MailboxManager : public base::RefCounted<MailboxManager> {
   // iterator in the MailboxToTextureMap to be able to manage changes to
   // the TextureToMailboxMap efficiently.
   typedef std::multimap<Texture*, TargetName> TextureToMailboxMap;
-  typedef std::map<TargetName,
-                   TextureToMailboxMap::iterator,
-                   std::pointer_to_binary_function<const TargetName&,
-                                                   const TargetName&,
-                                                   bool> > MailboxToTextureMap;
+  typedef std::map<
+      TargetName,
+      TextureToMailboxMap::iterator,
+      std::pointer_to_binary_function<
+          const TargetName&, const TargetName&, bool> > MailboxToTextureMap;
 
   MailboxToTextureMap mailbox_to_textures_;
   TextureToMailboxMap textures_to_mailboxes_;
@@ -80,3 +80,4 @@ class GPU_EXPORT MailboxManager : public base::RefCounted<MailboxManager> {
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_MAILBOX_MANAGER_H_
 
+
diff --git a/ui/compositor/compositor.cc b/ui/compositor/compositor.cc
index 37a147a..7061599 100644
--- a/ui/compositor/compositor.cc
+++ b/ui/compositor/compositor.cc
@@ -92,8 +92,8 @@ Texture::Texture(bool flipped, const gfx::Size& size, float device_scale_factor)
 Texture::~Texture() {
 }
 
-gpu::Mailbox Texture::Produce() {
-  return gpu::Mailbox();
+std::string Texture::Produce() {
+  return std::string();
 }
 
 CompositorLock::CompositorLock(Compositor* compositor)
diff --git a/ui/compositor/compositor.gyp b/ui/compositor/compositor.gyp
index a1a1b20..e1bd763 100644
--- a/ui/compositor/compositor.gyp
+++ b/ui/compositor/compositor.gyp
@@ -14,7 +14,6 @@
         '<(DEPTH)/base/base.gyp:base',
         '<(DEPTH)/base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
         '<(DEPTH)/cc/cc.gyp:cc',
-        '<(DEPTH)/gpu/gpu.gyp:command_buffer_common',
         '<(DEPTH)/skia/skia.gyp:skia',
         '<(DEPTH)/ui/gfx/gfx.gyp:gfx',
         '<(DEPTH)/ui/gfx/gfx.gyp:gfx_geometry',
diff --git a/ui/compositor/compositor.h b/ui/compositor/compositor.h
index 21c582e..84ed365 100644
--- a/ui/compositor/compositor.h
+++ b/ui/compositor/compositor.h
@@ -40,10 +40,6 @@ class Rect;
 class Size;
 }
 
-namespace gpu {
-struct Mailbox;
-}
-
 namespace ui {
 
 class Compositor;
@@ -116,12 +112,12 @@ class COMPOSITOR_EXPORT Texture : public base::RefCounted<Texture> {
   virtual unsigned int PrepareTexture() = 0;
 
   // Replaces the texture with the texture from the specified mailbox.
-  virtual void Consume(const gpu::Mailbox& mailbox,
+  virtual void Consume(const std::string& mailbox_name,
                        const gfx::Size& new_size) {}
 
   // Moves the texture into the mailbox and returns the mailbox name.
   // The texture must have been previously consumed from a mailbox.
-  virtual gpu::Mailbox Produce();
+  virtual std::string Produce();
 
  protected:
   virtual ~Texture();