Add PERSISTENT_MAP usage for GpuMemoryBuffers.

content/common/child_process_host_impl.cc

Index: content/common/child_process_host_impl.cc
diff --git a/content/common/child_process_host_impl.cc b/content/common/child_process_host_impl.cc
index 69a63507f5866808d58339dc9aa9f17ccc654caa..a398cda6d026d1ca13881d7ee2e5e09e7a88631d 100644
--- a/content/common/child_process_host_impl.cc
+++ b/content/common/child_process_host_impl.cc
@@ -322,14 +322,14 @@ void ChildProcessHostImpl::OnAllocateGpuMemoryBuffer(
   // AllocateForChildProcess() will check if |width| and |height| are valid
   // and handle failure in a controlled way when not. We just need to make
   // sure |format| and |usage| are supported here.
-  if (GpuMemoryBufferImplSharedMemory::IsFormatSupported(format) &&
-      usage == gfx::GpuMemoryBuffer::MAP) {
-    *handle = GpuMemoryBufferImplSharedMemory::AllocateForChildProcess(
-        g_next_gpu_memory_buffer_id.GetNext(),
-        gfx::Size(width, height),
-        format,
-        peer_process_.Handle());
-  }
+  if (!GpuMemoryBufferImplSharedMemory::IsFormatSupported(format))
+    return;
+  if (usage != gfx::GpuMemoryBuffer::MAP &&
+      usage != gfx::GpuMemoryBuffer::PERSISTENT_MAP)
+    return;
+  *handle = GpuMemoryBufferImplSharedMemory::AllocateForChildProcess(
+      g_next_gpu_memory_buffer_id.GetNext(), gfx::Size(width, height), format,
+      peer_process_.Handle());
 }
 
 void ChildProcessHostImpl::OnDeletedGpuMemoryBuffer(