content: Cleanup GpuMemoryBufferImpl destruction.

content/common/gpu/client/gpu_memory_buffer_impl_shared_memory.cc

Index: content/common/gpu/client/gpu_memory_buffer_impl_shared_memory.cc
diff --git a/content/common/gpu/client/gpu_memory_buffer_impl_shared_memory.cc b/content/common/gpu/client/gpu_memory_buffer_impl_shared_memory.cc
index 4c1534db191be9824d9603454e1fd2e762f06936..7f9b18d69657546830dee2137649ed9df43f4d3c 100644
--- a/content/common/gpu/client/gpu_memory_buffer_impl_shared_memory.cc
+++ b/content/common/gpu/client/gpu_memory_buffer_impl_shared_memory.cc
@@ -4,18 +4,31 @@
 
 #include "content/common/gpu/client/gpu_memory_buffer_impl_shared_memory.h"
 
+#include "base/bind.h"
 #include "base/numerics/safe_math.h"
 #include "ui/gl/gl_bindings.h"
 
 namespace content {
+namespace {
+
+void Noop() {
+}
+
+}  // namespace
 
 GpuMemoryBufferImplSharedMemory::GpuMemoryBufferImplSharedMemory(
     const gfx::Size& size,
-    unsigned internalformat)
-    : GpuMemoryBufferImpl(size, internalformat) {
+    unsigned internalformat,
+    const DestructionCallback& callback)
+    : GpuMemoryBufferImpl(size, internalformat), callback_(callback) {
 }
 
 GpuMemoryBufferImplSharedMemory::~GpuMemoryBufferImplSharedMemory() {
+  if (!shared_memory_)
+    return;
+
+  // Call destruction callback if instance was successfully initialized.
+  callback_.Run();
 }
 
 // static
@@ -27,7 +40,8 @@ void GpuMemoryBufferImplSharedMemory::Create(const gfx::Size& size,
       size, internalformat, usage));
 
   scoped_ptr<GpuMemoryBufferImplSharedMemory> buffer(
-      new GpuMemoryBufferImplSharedMemory(size, internalformat));
+      new GpuMemoryBufferImplSharedMemory(
+          size, internalformat, base::Bind(&Noop)));
   if (buffer->Initialize()) {
     callback.Run(buffer.PassAs<GpuMemoryBufferImpl>());
     return;