Re-land: ui: Add custom stride support to GLImageMemory.

ui/gl/gl_image_shared_memory.cc

 // Copyright 2014 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/gl/gl_image_shared_memory.h"
 
 #include "base/logging.h"
 #include "base/memory/shared_memory.h"
 #include "base/numerics/safe_math.h"
 #include "base/process/process_handle.h"
@@ skipping 10 matching lines @@
     : GLImageMemory(size, internalformat) {}
 
 GLImageSharedMemory::~GLImageSharedMemory() {
   DCHECK(!shared_memory_);
 }
 
 bool GLImageSharedMemory::Initialize(
     const base::SharedMemoryHandle& handle,
     gfx::GenericSharedMemoryId shared_memory_id,
     gfx::BufferFormat format,
-    size_t offset) {
-  size_t size_in_bytes;
-  if (!BufferSizeForBufferFormatChecked(GetSize(), format, &size_in_bytes))
+    size_t offset,
+    size_t stride) {
+  if (NumberOfPlanesForBufferFormat(format) != 1)
+    return false;
+
+  base::CheckedNumeric<size_t> checked_size = stride;
+  checked_size *= GetSize().height();
+  if (!checked_size.IsValid())
     return false;
 
   if (!base::SharedMemory::IsHandleValid(handle))
     return false;
 
   base::SharedMemory shared_memory(handle, true);
 
   // Duplicate the handle.
   base::SharedMemoryHandle duped_shared_memory_handle;
   if (!shared_memory.ShareToProcess(base::GetCurrentProcessHandle(),
                                     &duped_shared_memory_handle)) {
     DVLOG(0) << "Failed to duplicate shared memory handle.";
     return false;
   }
 
   // Minimize the amount of adress space we use but make sure offset is a
   // multiple of page size as required by MapAt().
   size_t memory_offset = offset % base::SysInfo::VMAllocationGranularity();
   size_t map_offset = base::SysInfo::VMAllocationGranularity() *
                       (offset / base::SysInfo::VMAllocationGranularity());
 
-  base::CheckedNumeric<size_t> checked_size_to_map_in_bytes = size_in_bytes;
-  checked_size_to_map_in_bytes += memory_offset;
-  if (!checked_size_to_map_in_bytes.IsValid())
+  checked_size += memory_offset;
+  if (!checked_size.IsValid())
     return false;
 
   scoped_ptr<base::SharedMemory> duped_shared_memory(
       new base::SharedMemory(duped_shared_memory_handle, true));
   if (!duped_shared_memory->MapAt(static_cast<off_t>(map_offset),
-                                  checked_size_to_map_in_bytes.ValueOrDie())) {
+                                  checked_size.ValueOrDie())) {
     DVLOG(0) << "Failed to map shared memory.";
     return false;
   }
 
   if (!GLImageMemory::Initialize(
           static_cast<uint8_t*>(duped_shared_memory->memory()) + memory_offset,
-          format)) {
+          format, stride)) {
     return false;
   }
 
   DCHECK(!shared_memory_);
   shared_memory_ = duped_shared_memory.Pass();
   shared_memory_id_ = shared_memory_id;
   return true;
 }
 
 void GLImageSharedMemory::Destroy(bool have_context) {
   GLImageMemory::Destroy(have_context);
   shared_memory_.reset();
 }
 
 void GLImageSharedMemory::OnMemoryDump(
     base::trace_event::ProcessMemoryDump* pmd,
     uint64_t process_tracing_id,
     const std::string& dump_name) {
   size_t size_in_bytes = 0;
 
   if (shared_memory_)
-    size_in_bytes = BufferSizeForBufferFormat(GetSize(), format());
+    size_in_bytes = stride() * GetSize().height();
 
   // Dump under "/shared_memory", as the base class may also dump to
   // "/texture_memory".
   base::trace_event::MemoryAllocatorDump* dump =
       pmd->CreateAllocatorDump(dump_name + "/shared_memory");
   dump->AddScalar(base::trace_event::MemoryAllocatorDump::kNameSize,
                   base::trace_event::MemoryAllocatorDump::kUnitsBytes,
                   static_cast<uint64_t>(size_in_bytes));
 
   auto guid = GetGenericSharedMemoryGUIDForTracing(process_tracing_id,
                                                    shared_memory_id_);
   pmd->CreateSharedGlobalAllocatorDump(guid);
   pmd->AddOwnershipEdge(dump->guid(), guid);
 }
 
 }  // namespace gl