Use mapped memory for uploading large textures.

gpu/command_buffer/client/mapped_memory.cc

 // Copyright (c) 2011 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 "gpu/command_buffer/client/mapped_memory.h"
 
 #include <algorithm>
 #include <functional>
 
 #include "base/logging.h"
@@ skipping 122 matching lines @@
     if (!chunk->InUse()) {
       cmd_buf->DestroyTransferBuffer(chunk->shm_id());
       allocated_memory_ -= chunk->GetSize();
       iter = chunks_.erase(iter);
     } else {
       ++iter;
     }
   }
 }
 
+void ScopedMappedMemoryPtr::Release() {
+  if (buffer_) {
+    mapped_memory_manager_->FreePendingToken(buffer_, helper_->InsertToken());
+    buffer_ = nullptr;
+    size_ = 0;
+    shm_id_ = 0;
+    shm_offset_ = 0;
+
+    if (flush_after_release_)
+      helper_->CommandBufferHelper::Flush();
+  }
+}
+
+void ScopedMappedMemoryPtr::Reset(unsigned int new_size) {
+  Release();
+
+  if (new_size) {
+    buffer_ = mapped_memory_manager_->Alloc(size_, &shm_id_, &shm_offset_);
+    size_ = buffer_ ? new_size : 0;
+  }
+}
+
 }  // namespace gpu