Replace usage of WebVector::isEmpty with WebVector::empty().

media/blink/key_system_config_selector.cc

Index: media/blink/key_system_config_selector.cc
diff --git a/media/blink/key_system_config_selector.cc b/media/blink/key_system_config_selector.cc
index 5fcd5675bbc0a0218e8695e5cfb3c00ab8ae8cc2..03b60d6b620ed7997bf18e39de8d506b8163b3a4 100644
--- a/media/blink/key_system_config_selector.cc
+++ b/media/blink/key_system_config_selector.cc
@@ -461,7 +461,7 @@ KeySystemConfigSelector::GetSupportedConfiguration(
 
   // 3. If the initDataTypes member of candidate configuration is non-empty,
   //    run the following steps:
-  if (!candidate.initDataTypes.isEmpty()) {
+  if (!candidate.initDataTypes.empty()) {
     // 3.1. Let supported types be an empty sequence of DOMStrings.
     std::vector<blink::WebEncryptedMediaInitDataType> supported_types;
 
@@ -650,8 +650,8 @@ KeySystemConfigSelector::GetSupportedConfiguration(
 
   // 15. If the videoCapabilities and audioCapabilities members in candidate
   //     configuration are both empty, return NotSupported.
-  if (candidate.videoCapabilities.isEmpty() &&
-      candidate.audioCapabilities.isEmpty()) {
+  if (candidate.videoCapabilities.empty() &&
+      candidate.audioCapabilities.empty()) {
     DVLOG(2) << "Rejecting requested configuration because "
              << "neither audioCapabilities nor videoCapabilities is specified";
     return CONFIGURATION_NOT_SUPPORTED;
@@ -660,7 +660,7 @@ KeySystemConfigSelector::GetSupportedConfiguration(
   // 16. If the videoCapabilities member in candidate configuration is
   //     non-empty:
   std::vector<blink::WebMediaKeySystemMediaCapability> video_capabilities;
-  if (!candidate.videoCapabilities.isEmpty()) {
+  if (!candidate.videoCapabilities.empty()) {
     // 16.1. Let video capabilities be the result of executing the Get
     //       Supported Capabilities for Audio/Video Type algorithm on Video,
     //       candidate configuration's videoCapabilities member, accumulated
@@ -684,7 +684,7 @@ KeySystemConfigSelector::GetSupportedConfiguration(
   // 17. If the audioCapabilities member in candidate configuration is
   //     non-empty:
   std::vector<blink::WebMediaKeySystemMediaCapability> audio_capabilities;
-  if (!candidate.audioCapabilities.isEmpty()) {
+  if (!candidate.audioCapabilities.empty()) {
     // 17.1. Let audio capabilities be the result of executing the Get
     //       Supported Capabilities for Audio/Video Type algorithm on Audio,
     //       candidate configuration's audioCapabilities member, accumulated