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

content/common/child_process_messages.h

Index: content/common/child_process_messages.h
diff --git a/content/common/child_process_messages.h b/content/common/child_process_messages.h
index cbe6d9b6fdb836a32b56e5ed5f35003d4fa16694..91733d6db2f18c17d5f25c2079e9a01d8666ee03 100644
--- a/content/common/child_process_messages.h
+++ b/content/common/child_process_messages.h
@@ -179,23 +179,6 @@
 IPC_MESSAGE_CONTROL0(ChildProcessHostMsg_ReleaseCachedFonts)
 #endif  // defined(OS_WIN)
 
-// Asks the browser to create a block of shared memory for the child process to
-// fill in and pass back to the browser.
-IPC_SYNC_MESSAGE_CONTROL2_1(ChildProcessHostMsg_SyncAllocateSharedBitmap,
-                            uint32_t /* buffer size */,
-                            cc::SharedBitmapId,
-                            base::SharedMemoryHandle)
-
-// Informs the browser that the child allocated a shared bitmap.
-IPC_MESSAGE_CONTROL3(ChildProcessHostMsg_AllocatedSharedBitmap,
-                     uint32_t /* buffer size */,
-                     base::SharedMemoryHandle,
-                     cc::SharedBitmapId)
-
-// Informs the browser that the child deleted a shared bitmap.
-IPC_MESSAGE_CONTROL1(ChildProcessHostMsg_DeletedSharedBitmap,
-                     cc::SharedBitmapId)
-
 // Asks the browser to create a gpu memory buffer.
 IPC_SYNC_MESSAGE_CONTROL5_1(ChildProcessHostMsg_SyncAllocateGpuMemoryBuffer,
                             gfx::GpuMemoryBufferId /* new_id */,