components: Add out-of-line copy ctors for complex classes.

components/gcm_driver/gcm_client.cc

Index: components/gcm_driver/gcm_client.cc
diff --git a/components/gcm_driver/gcm_client.cc b/components/gcm_driver/gcm_client.cc
index 33271bacd66f15b1c4e29736194e15f06717757e..1208a916b821724189c588e757b56f28c462b830 100644
--- a/components/gcm_driver/gcm_client.cc
+++ b/components/gcm_driver/gcm_client.cc
@@ -16,6 +16,9 @@ GCMClient::ChromeBuildInfo::~ChromeBuildInfo() {
 
 GCMClient::SendErrorDetails::SendErrorDetails() : result(UNKNOWN_ERROR) {}
 
+GCMClient::SendErrorDetails::SendErrorDetails(const SendErrorDetails& other) =
+    default;
+
 GCMClient::SendErrorDetails::~SendErrorDetails() {}
 
 GCMClient::GCMStatistics::GCMStatistics()
@@ -27,6 +30,8 @@ GCMClient::GCMStatistics::GCMStatistics()
       resend_queue_size(0) {
 }
 
+GCMClient::GCMStatistics::GCMStatistics(const GCMStatistics& other) = default;
+
 GCMClient::GCMStatistics::~GCMStatistics() {
 }