Refactor how WebCrypto NSS and OpenSSL specific files are included by GN build.

This is in anticipation of adding more crypto-library specific files, so the file lists are not duplicated

BUG=374912
R=brettw@chromium.org, dpranke@chromium.org

Review URL: https://codereview.chromium.org/395643002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@283510 0039d316-1c4b-4281-b951-d872f2087c98

content/child/BUILD.gn

@@ -107,8 +107,10 @@ source_set("child") {
   }
 
   if (!use_openssl) {
-    sources -= [ "webcrypto/platform_crypto_openssl.cc" ]
+    sources += rebase_path(content_child_gypi_values.webcrypto_nss_sources,
+                           ".", "//content")
   } else {
-    sources -= [ "webcrypto/platform_crypto_nss.cc" ]
+    sources += rebase_path(content_child_gypi_values.webcrypto_openssl_sources,
+                           ".", "//content")
   }
 }

content/content_child.gypi

@@ -200,8 +200,6 @@
       'child/webcrypto/jwk.cc',
       'child/webcrypto/jwk.h',
       'child/webcrypto/platform_crypto.h',
-      'child/webcrypto/platform_crypto_nss.cc',
-      'child/webcrypto/platform_crypto_openssl.cc',
       'child/webcrypto/shared_crypto.cc',
       'child/webcrypto/shared_crypto.h',
       'child/webcrypto/status.cc',
@@ -235,6 +233,12 @@
       'child/worker_thread_task_runner.cc',
       'child/worker_thread_task_runner.h',
     ],
+    'webcrypto_nss_sources': [
+      'child/webcrypto/platform_crypto_nss.cc',
+    ],
+    'webcrypto_openssl_sources': [
+      'child/webcrypto/platform_crypto_openssl.cc',
+    ],
   },
   'sources': [
     '<@(public_child_sources)',
@@ -289,15 +293,15 @@
       ],
     }],
     ['use_openssl==1', {
-      'sources!': [
-        'child/webcrypto/platform_crypto_nss.cc',
+      'sources': [
+        '<@(webcrypto_openssl_sources)',
       ],
       'dependencies': [
         '../third_party/openssl/openssl.gyp:openssl',
       ],
     }, {
-      'sources!': [
-        'child/webcrypto/platform_crypto_openssl.cc',
+      'sources': [
+        '<@(webcrypto_nss_sources)',
       ],
       'conditions': [
         ['os_posix == 1 and OS != "mac" and OS != "ios" and OS != "android"', {