Reland of placing allocate bitmap IPC messages with a new Mojo interface.

content/child/child_shared_bitmap_manager.cc

Index: content/child/child_shared_bitmap_manager.cc
diff --git a/content/child/child_shared_bitmap_manager.cc b/content/child/child_shared_bitmap_manager.cc
index 00b461c7e96baad1d89e7d8717ff523cdaf132b4..b0a46299d8951f66b64ca92a966f5a6b532a65ad 100644
--- a/content/child/child_shared_bitmap_manager.cc
+++ b/content/child/child_shared_bitmap_manager.cc
@@ -15,6 +15,7 @@
 #include "build/build_config.h"
 #include "content/child/child_thread_impl.h"
 #include "content/common/child_process_messages.h"
+#include "mojo/public/cpp/system/platform_handle.h"
 #include "ui/gfx/geometry/size.h"
 
 namespace content {
@@ -23,27 +24,34 @@
 
 class ChildSharedBitmap : public SharedMemoryBitmap {
  public:
-  ChildSharedBitmap(scoped_refptr<ThreadSafeSender> sender,
-                    base::SharedMemory* shared_memory,
-                    const cc::SharedBitmapId& id)
+  ChildSharedBitmap(
+      const scoped_refptr<mojom::ThreadSafeRenderMessageFilterAssociatedPtr>&
+          render_message_filter_ptr,
+      base::SharedMemory* shared_memory,
+      const cc::SharedBitmapId& id)
       : SharedMemoryBitmap(static_cast<uint8_t*>(shared_memory->memory()),
                            id,
                            shared_memory),
-        sender_(sender) {}
+        render_message_filter_ptr_(render_message_filter_ptr) {}
 
-  ChildSharedBitmap(scoped_refptr<ThreadSafeSender> sender,
-                    std::unique_ptr<base::SharedMemory> shared_memory_holder,
-                    const cc::SharedBitmapId& id)
-      : ChildSharedBitmap(sender, shared_memory_holder.get(), id) {
+  ChildSharedBitmap(
+      const scoped_refptr<mojom::ThreadSafeRenderMessageFilterAssociatedPtr>&
+          render_message_filter_ptr,
+      std::unique_ptr<base::SharedMemory> shared_memory_holder,
+      const cc::SharedBitmapId& id)
+      : ChildSharedBitmap(render_message_filter_ptr,
+                          shared_memory_holder.get(),
+                          id) {
     shared_memory_holder_ = std::move(shared_memory_holder);
   }
 
   ~ChildSharedBitmap() override {
-    sender_->Send(new ChildProcessHostMsg_DeletedSharedBitmap(id()));
+    (*render_message_filter_ptr_)->DeletedSharedBitmap(id());
   }
 
  private:
-  scoped_refptr<ThreadSafeSender> sender_;
+  scoped_refptr<mojom::ThreadSafeRenderMessageFilterAssociatedPtr>
+      render_message_filter_ptr_;
   std::unique_ptr<base::SharedMemory> shared_memory_holder_;
 };
 
@@ -79,25 +87,14 @@
     : SharedBitmap(pixels, id), shared_memory_(shared_memory) {}
 
 ChildSharedBitmapManager::ChildSharedBitmapManager(
-    scoped_refptr<ThreadSafeSender> sender)
-    : sender_(sender) {
-}
+    const scoped_refptr<mojom::ThreadSafeRenderMessageFilterAssociatedPtr>&
+        render_message_filter_ptr)
+    : render_message_filter_ptr_(render_message_filter_ptr) {}
 
 ChildSharedBitmapManager::~ChildSharedBitmapManager() {}
 
 std::unique_ptr<cc::SharedBitmap>
 ChildSharedBitmapManager::AllocateSharedBitmap(const gfx::Size& size) {
-  std::unique_ptr<SharedMemoryBitmap> bitmap = AllocateSharedMemoryBitmap(size);
-#if defined(OS_POSIX)
-  // Close file descriptor to avoid running out.
-  if (bitmap)
-    bitmap->shared_memory()->Close();
-#endif
-  return std::move(bitmap);
-}
-
-std::unique_ptr<SharedMemoryBitmap>
-ChildSharedBitmapManager::AllocateSharedMemoryBitmap(const gfx::Size& size) {
   TRACE_EVENT2("renderer",
                "ChildSharedBitmapManager::AllocateSharedMemoryBitmap", "width",
                size.width(), "height", size.height());
@@ -105,25 +102,10 @@
   if (!cc::SharedBitmap::SizeInBytes(size, &memory_size))
     return std::unique_ptr<SharedMemoryBitmap>();
   cc::SharedBitmapId id = cc::SharedBitmap::GenerateId();
-  std::unique_ptr<base::SharedMemory> memory;
-#if defined(OS_POSIX)
-  base::SharedMemoryHandle handle;
-  bool send_success =
-      sender_->Send(new ChildProcessHostMsg_SyncAllocateSharedBitmap(
-          memory_size, id, &handle));
-  if (!send_success) {
-    // Callers of this method are not prepared to handle failures during
-    // shutdown. Exit immediately. This is expected behavior during the Fast
-    // Shutdown path, so use EXIT_SUCCESS. https://crbug.com/615121.
-    exit(EXIT_SUCCESS);
-  }
-  memory = base::MakeUnique<base::SharedMemory>(handle, false);
-  if (!memory->Map(memory_size))
-    CollectMemoryUsageAndDie(size, memory_size);
-#else
-  bool out_of_memory;
-  memory = ChildThreadImpl::AllocateSharedMemory(memory_size, sender_.get(),
-                                                 &out_of_memory);
+  bool out_of_memory = false;
+  std::unique_ptr<base::SharedMemory> memory =
+      ChildThreadImpl::AllocateSharedMemory(memory_size, nullptr,
+                                            &out_of_memory);
   if (!memory) {
     if (out_of_memory) {
       CollectMemoryUsageAndDie(size, memory_size);
@@ -138,11 +120,14 @@
   if (!memory->Map(memory_size))
     CollectMemoryUsageAndDie(size, memory_size);
 
-  base::SharedMemoryHandle handle_to_send = memory->handle();
-  sender_->Send(new ChildProcessHostMsg_AllocatedSharedBitmap(
-      memory_size, handle_to_send, id));
-#endif
-  return base::MakeUnique<ChildSharedBitmap>(sender_, std::move(memory), id);
+  NotifyAllocatedSharedBitmap(memory.get(), id);
+
+  // Close the associated FD to save resources, the previously mapped memory
+  // remains available.
+  memory->Close();
+
+  return base::MakeUnique<ChildSharedBitmap>(render_message_filter_ptr_,
+                                             std::move(memory), id);
 }
 
 std::unique_ptr<cc::SharedBitmap>
@@ -155,15 +140,28 @@
 std::unique_ptr<cc::SharedBitmap>
 ChildSharedBitmapManager::GetBitmapForSharedMemory(base::SharedMemory* mem) {
   cc::SharedBitmapId id = cc::SharedBitmap::GenerateId();
-  base::SharedMemoryHandle handle_to_send = mem->handle();
-#if defined(OS_POSIX)
-  if (!mem->ShareToProcess(base::GetCurrentProcessHandle(), &handle_to_send))
-    return std::unique_ptr<cc::SharedBitmap>();
-#endif
-  sender_->Send(new ChildProcessHostMsg_AllocatedSharedBitmap(
-      mem->mapped_size(), handle_to_send, id));
+  NotifyAllocatedSharedBitmap(mem, cc::SharedBitmap::GenerateId());
+  return base::MakeUnique<ChildSharedBitmap>(render_message_filter_ptr_,
+                                             std::move(mem), id);
+}
 
-  return base::MakeUnique<ChildSharedBitmap>(sender_, mem, id);
+// Notifies the browser process that a shared bitmap with the given ID was
+// allocated. Caller keeps ownership of |memory|.
+void ChildSharedBitmapManager::NotifyAllocatedSharedBitmap(
+    base::SharedMemory* memory,
+    const cc::SharedBitmapId& id) {
+  base::SharedMemoryHandle handle_to_send =
+      base::SharedMemory::DuplicateHandle(memory->handle());
+  if (!base::SharedMemory::IsHandleValid(handle_to_send)) {
+    LOG(ERROR) << "Failed to duplicate shared memory handle for bitmap.";
+    return;
+  }
+
+  mojo::ScopedSharedBufferHandle buffer_handle = mojo::WrapSharedMemoryHandle(
+      handle_to_send, memory->mapped_size(), true /* read_only */);
+
+  (*render_message_filter_ptr_)
+      ->AllocatedSharedBitmap(std::move(buffer_handle), id);
 }
 
 }  // namespace content