Ensure memory mapped chunk size is aligned with the FencedAllocator.

gpu/command_buffer/client/gles2_implementation.cc

 // Copyright (c) 2012 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.
 
 // A class to emulate GLES2 over command buffers.
 
 #include "gpu/command_buffer/client/gles2_implementation.h"
 
 #include <GLES2/gl2.h>
 #include <GLES2/gl2ext.h>
 #include <GLES2/gl2extchromium.h>
 #include <GLES3/gl3.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <algorithm>
 #include <map>
 #include <set>
 #include <sstream>
 #include <string>
 #include "base/atomic_sequence_num.h"
+#include "base/bits.h"
 #include "base/compiler_specific.h"
 #include "base/numerics/safe_math.h"
 #include "base/strings/string_split.h"
 #include "base/strings/stringprintf.h"
 #include "base/sys_info.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/trace_event/memory_allocator_dump.h"
 #include "base/trace_event/memory_dump_manager.h"
 #include "base/trace_event/process_memory_dump.h"
 #include "base/trace_event/trace_event.h"
@@ skipping 181 matching lines @@
       kSizeToFlush)) {
     return false;
   }
 
   mapped_memory_.reset(new MappedMemoryManager(helper_, mapped_memory_limit));
 
   unsigned chunk_size = 2 * 1024 * 1024;
   if (mapped_memory_limit != SharedMemoryLimits::kNoLimit) {
     // Use smaller chunks if the client is very memory conscientious.
     chunk_size = std::min(mapped_memory_limit / 4, chunk_size);
+    chunk_size = base::bits::Align(chunk_size,
+                                   FencedAllocator::kAllocAlignment);
   }
   mapped_memory_->set_chunk_size_multiple(chunk_size);
 
   GLStaticState::ShaderPrecisionMap* shader_precisions =
       &static_state_.shader_precisions;
   capabilities_.VisitPrecisions([shader_precisions](
       GLenum shader, GLenum type, Capabilities::ShaderPrecision* result) {
     const GLStaticState::ShaderPrecisionKey key(shader, type);
     cmds::GetShaderPrecisionFormat::Result cached_result = {
         true, result->min_range, result->max_range, result->precision};
@@ skipping 6837 matching lines @@
   CheckGLError();
 }
 
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.
 #include "gpu/command_buffer/client/gles2_implementation_impl_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu