GN: Remove dependency on //base for gmock.

tools/gn/secondary/testing/gmock/BUILD.gn

Index: tools/gn/secondary/testing/gmock/BUILD.gn
diff --git a/tools/gn/secondary/testing/gmock/BUILD.gn b/tools/gn/secondary/testing/gmock/BUILD.gn
index 8b5f8dbeb9ba68af467398bce2decb23477bd102..e682abf58bf18d738ae4132f92f8ca020bf58737 100644
--- a/tools/gn/secondary/testing/gmock/BUILD.gn
+++ b/tools/gn/secondary/testing/gmock/BUILD.gn
@@ -28,7 +28,6 @@ static_library("gmock") {
     "src/gmock-matchers.cc",
     "src/gmock-spec-builders.cc",
     "src/gmock.cc",
-    "../gmock_mutant.h",  # gMock helpers
   ]
 
   # This project includes some stuff form gtest's guts.
@@ -38,8 +37,6 @@ static_library("gmock") {
     ":gmock_config",
     "//testing/gtest:gtest_config",
   ]
-
-  deps = [ "//base" ]
 }
 
 static_library("gmock_main") {