Add a function for determining if official Google Chrome API key is used.

I'd like to add this for handling several features of Google Drive API
that is only available for whitelisted first-party client.
By checking the key by the newly added function, we can provide
better fallbacks for clients with third-party keys, instead of just failing.

BUG=332332, 324166

Review URL: https://codereview.chromium.org/131743018

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245504 0039d316-1c4b-4281-b951-d872f2087c98

google_apis/google_api_keys.cc

@@ -269,4 +269,12 @@ std::string GetOAuth2ClientSecret(OAuth2Client client) {
   return g_api_key_cache.Get().GetClientSecret(client);
 }
 
+bool IsGoogleChromeAPIKeyUsed() {
+#if defined(GOOGLE_CHROME_BUILD) || defined(USE_OFFICIAL_GOOGLE_API_KEYS)
+  return true;
+#else
+  return false;
+#endif
+}
+
 }  // namespace google_apis

google_apis/google_api_keys.h

@@ -90,6 +90,10 @@ std::string GetOAuth2ClientID(OAuth2Client client);
 // in, e.g. URL-escaped if you use it in a URL.
 std::string GetOAuth2ClientSecret(OAuth2Client client);
 
+// Returns if the API key using in the current build is the one for official
+// Google Chrome.
+bool IsGoogleChromeAPIKeyUsed();
+
 }  // namespace google_apis
 
 #endif  // GOOGLE_APIS_GOOGLE_API_KEYS_H_