Simplify base/BUILD.gn rules for shared_memory_* files.

base/memory/shared_memory_posix.cc was especially confusing because on
iOS it was removed and then re-added to the sources list.

Change-Id: I689911144a6116e1129b2ecb5e9b90db791a7e8f
Reviewed-on: https://chromium-review.googlesource.com/794450Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#520207}

base/BUILD.gn

@@ -516,20 +516,12 @@ jumbo_component("base") {
     "memory/scoped_policy.h",
     "memory/scoped_refptr.h",
     "memory/shared_memory.h",
-    "memory/shared_memory_android.cc",
     "memory/shared_memory_handle.cc",
     "memory/shared_memory_handle.h",
-    "memory/shared_memory_handle_android.cc",
-    "memory/shared_memory_handle_mac.cc",
-    "memory/shared_memory_handle_win.cc",
     "memory/shared_memory_helper.cc",
     "memory/shared_memory_helper.h",
-    "memory/shared_memory_mac.cc",
-    "memory/shared_memory_nacl.cc",
-    "memory/shared_memory_posix.cc",
     "memory/shared_memory_tracker.cc",
     "memory/shared_memory_tracker.h",
-    "memory/shared_memory_win.cc",
     "memory/singleton.cc",
     "memory/singleton.h",
     "memory/weak_ptr.cc",
@@ -1131,12 +1123,6 @@ jumbo_component("base") {
     }
   }
 
-  # MacOS and Android have their own custom shared memory implementations due
-  # to supporting both POSIX and native handles.
-  if (is_posix && !is_mac && !is_android) {
-    sources += [ "memory/shared_memory_handle_posix.cc" ]
-  }
-
   all_dependent_configs = []
   defines = []
   data = []
@@ -1218,6 +1204,10 @@ jumbo_component("base") {
   # Android.
   if (is_android) {
     sources -= [ "debug/stack_trace_posix.cc" ]
+    sources += [
+      "memory/shared_memory_android.cc",
+      "memory/shared_memory_handle_android.cc",
+    ]
 
     # Android uses some Linux sources, put those back.
     set_sources_assignment_filter([])
@@ -1258,8 +1248,6 @@ jumbo_component("base") {
     # below, rather than using the generic POSIX or Linux-y ones.
     sources -= [
       "debug/stack_trace_posix.cc",
-      "memory/shared_memory_handle_posix.cc",
-      "memory/shared_memory_posix.cc",
       "message_loop/message_pump_libevent.cc",
       "message_loop/message_pump_libevent.h",
       "posix/unix_domain_socket.cc",
@@ -1309,6 +1297,7 @@ jumbo_component("base") {
     set_sources_assignment_filter([])
     sources += [
       "files/file_path_watcher_stub.cc",
+      "memory/shared_memory_nacl.cc",
       "process/process_metrics_nacl.cc",
       "sync_socket_nacl.cc",
       "threading/platform_thread_linux.cc",
@@ -1335,7 +1324,6 @@ jumbo_component("base") {
       "memory/discardable_shared_memory.h",
       "memory/shared_memory_helper.cc",
       "memory/shared_memory_helper.h",
-      "memory/shared_memory_posix.cc",
       "native_library.cc",
       "native_library_posix.cc",
       "path_service.cc",
@@ -1389,7 +1377,6 @@ jumbo_component("base") {
   } else {
     # Remove NaCl stuff.
     sources -= [
-      "memory/shared_memory_nacl.cc",
       "os_compat_nacl.cc",
       "os_compat_nacl.h",
       "rand_util_nacl.cc",
@@ -1415,6 +1402,8 @@ jumbo_component("base") {
   # Windows.
   if (is_win) {
     sources += [
+      "memory/shared_memory_handle_win.cc",
+      "memory/shared_memory_win.cc",
       "power_monitor/power_monitor_device_source_win.cc",
       "profiler/win32_stack_frame_unwinder.cc",
       "profiler/win32_stack_frame_unwinder.h",
@@ -1530,8 +1519,11 @@ jumbo_component("base") {
 
   # Desktop Mac.
   if (is_mac) {
+    sources -= [ "profiler/native_stack_sampler_posix.cc" ]
     sources += [
       "mac/scoped_typeref.h",
+      "memory/shared_memory_handle_mac.cc",
+      "memory/shared_memory_mac.cc",
       "power_monitor/power_monitor_device_source_mac.mm",
       "time/time_conversion_posix.cc",
       "time/time_exploded_posix.cc",
@@ -1551,17 +1543,12 @@ jumbo_component("base") {
   # Mac or iOS.
   if (is_mac || is_ios) {
     sources -= [
-      "memory/shared_memory_posix.cc",
       "native_library_posix.cc",
       "strings/sys_string_conversions_posix.cc",
       "synchronization/waitable_event_posix.cc",
       "synchronization/waitable_event_watcher_posix.cc",
       "threading/platform_thread_internal_posix.cc",
     ]
-
-    if (is_mac) {
-      sources -= [ "profiler/native_stack_sampler_posix.cc" ]
-    }
   } else {
     # Non-Mac/ios.
     sources -= [
@@ -1670,7 +1657,6 @@ jumbo_component("base") {
       "mac/scoped_objc_class_swizzler.h",
       "mac/scoped_objc_class_swizzler.mm",
       "mac/scoped_typeref.h",
-      "memory/shared_memory_posix.cc",
       "message_loop/message_pump_mac.h",
       "message_loop/message_pump_mac.mm",
       "power_monitor/power_monitor_device_source_ios.mm",
@@ -1685,6 +1671,16 @@ jumbo_component("base") {
     set_sources_assignment_filter(sources_assignment_filter)
   }
 
+  # Android, Fuchsia, and MacOS have their own custom shared memory handle
+  # implementations. e.g. due to supporting both POSIX and native handles.
+  if (is_posix && !is_android && !is_fuchsia && !is_mac) {
+    sources += [ "memory/shared_memory_handle_posix.cc" ]
+  }
+
+  if (is_posix && !is_fuchsia && !is_mac && !is_nacl) {
+    sources += [ "memory/shared_memory_posix.cc" ]
+  }
+
   if (is_posix && !is_fuchsia && !is_mac && !is_ios) {
     sources += [
       "time/time_conversion_posix.cc",