Added release_extra_cflags only to the target compiles.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 62dad1474f80678c40b4d948b3e9da0ca15c164b..62329b3458a8f1fad4853164aaee9de706985917 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -1757,8 +1757,12 @@
         },
         'conditions': [
           ['OS=="linux"', {
-            'cflags': [
-              '<@(debug_extra_cflags)',
+            'target_conditions': [
+              ['_toolset=="target"', {
+                'cflags': [
+                  '<@(debug_extra_cflags)',
+                ],
+              }],
             ],
           }],
           ['release_valgrind_build==0', {
@@ -1849,8 +1853,12 @@
             'defines': ['NO_TCMALLOC'],
           }],
           ['OS=="linux"', {
-            'cflags': [
-             '<@(release_extra_cflags)',
+            'target_conditions': [
+              ['_toolset=="target"', {
+                'cflags': [
+                  '<@(release_extra_cflags)',
+                ],
+              }],
             ],
           }],
         ],