GN: Fix invalid configuration for Android GCC build.

The disabling of the sin,cos,sinf,cosf functions had the wrong
condition for GN. This fixes that and also makes the condition
in common.gypi a bit more readable.

BUG=
R=pbos@webrtc.org

Review URL: https://codereview.webrtc.org/1307633008 .

Cr-Commit-Position: refs/heads/master@{#9871}

webrtc/BUILD.gn

@@ -153,10 +153,7 @@ config("common_config") {
     }
   }
 
-  # TODO(kjellander): Handle warnings on Windows where WebRTC differ from the
-  # default warnings set in build/config/compiler/BUILD.gn.
-
-  if (is_android && is_clang) {
+  if (is_android && !is_clang) {
     # The Android NDK doesn"t provide optimized versions of these
     # functions. Ensure they are disabled for all compilers.
     cflags += [

webrtc/build/common.gypi

@@ -372,7 +372,7 @@
           'WEBRTC_ANDROID',
          ],
          'conditions': [
-           ['clang!=1', {
+           ['clang==0', {
              # The Android NDK doesn't provide optimized versions of these
              # functions. Ensure they are disabled for all compilers.
              'cflags': [