Add GenericSharedMemoryId and use w/ GpuMemoryBuffer

ui/gfx/gpu_memory_buffer.cc

Index: ui/gfx/gpu_memory_buffer.cc
diff --git a/ui/gfx/gpu_memory_buffer.cc b/ui/gfx/gpu_memory_buffer.cc
index 44fcd31fd87513868f5d135d32393f7f92fc545d..826eaca41edd6b25803787958cc68a0a4e908866 100644
--- a/ui/gfx/gpu_memory_buffer.cc
+++ b/ui/gfx/gpu_memory_buffer.cc
@@ -9,14 +9,6 @@
 
 namespace gfx {
 
-base::trace_event::MemoryAllocatorDumpGuid GetGpuMemoryBufferGUIDForTracing(
-    uint64 tracing_process_id,
-    GpuMemoryBufferId buffer_id) {
-  return base::trace_event::MemoryAllocatorDumpGuid(
-      base::StringPrintf("gpumemorybuffer-x-process/%" PRIx64 "/%d",
-                         tracing_process_id, buffer_id));
-}
-
 GpuMemoryBufferHandle::GpuMemoryBufferHandle()
     : type(EMPTY_BUFFER), id(0), handle(base::SharedMemory::NULLHandle()) {
 }