fuchsia: base_unittests (mostly) compiling

base/trace_event/process_memory_dump.cc

Index: base/trace_event/process_memory_dump.cc
diff --git a/base/trace_event/process_memory_dump.cc b/base/trace_event/process_memory_dump.cc
index d8a51ef4fe1e193415b3933a6c1e947b62303998..d81999c6c76eec2d14b8797f08da50001dde852e 100644
--- a/base/trace_event/process_memory_dump.cc
+++ b/base/trace_event/process_memory_dump.cc
@@ -116,6 +116,10 @@ size_t ProcessMemoryDump::CountResidentBytes(void* start_address,
 
     for (size_t i = 0; i < page_count; i++)
       resident_page_count += vec[i].VirtualAttributes.Valid;
+#elif defined(OS_FUCHSIA)
+    // TODO(fuchsia): Port, see https://crbug.com/706592.
+    ALLOW_UNUSED_LOCAL(chunk_start);
+    ALLOW_UNUSED_LOCAL(page_count);
 #elif defined(OS_POSIX)
     int error_counter = 0;
     int result = 0;