base: rename subprocess.cc -> subprocess_posix.cc

This is a pure file rename in preparation of aosp/1532423.
The only reason of this CL is to improve reviewability of the
other CL, Gerrit doesn't detect the rename there.

Bug: 174454879
Change-Id: Ia38a7c7bfd20ff0febdad8bf6dbdde1bca00ae7a
diff --git a/Android.bp b/Android.bp
index 95f5392..f6b5f15 100644
--- a/Android.bp
+++ b/Android.bp
@@ -6411,7 +6411,7 @@
     "src/base/string_splitter.cc",
     "src/base/string_utils.cc",
     "src/base/string_view.cc",
-    "src/base/subprocess.cc",
+    "src/base/subprocess_posix.cc",
     "src/base/temp_file.cc",
     "src/base/thread_checker.cc",
     "src/base/thread_task_runner.cc",
diff --git a/BUILD b/BUILD
index 8e63d57..31b8630 100644
--- a/BUILD
+++ b/BUILD
@@ -591,7 +591,7 @@
         "src/base/string_splitter.cc",
         "src/base/string_utils.cc",
         "src/base/string_view.cc",
-        "src/base/subprocess.cc",
+        "src/base/subprocess_posix.cc",
         "src/base/temp_file.cc",
         "src/base/thread_checker.cc",
         "src/base/thread_task_runner.cc",
diff --git a/src/base/BUILD.gn b/src/base/BUILD.gn
index 5dc7be4..d638f09 100644
--- a/src/base/BUILD.gn
+++ b/src/base/BUILD.gn
@@ -36,7 +36,7 @@
     "string_splitter.cc",
     "string_utils.cc",
     "string_view.cc",
-    "subprocess.cc",
+    "subprocess_posix.cc",
     "temp_file.cc",
     "thread_checker.cc",
     "time.cc",
diff --git a/src/base/subprocess.cc b/src/base/subprocess_posix.cc
similarity index 100%
rename from src/base/subprocess.cc
rename to src/base/subprocess_posix.cc