shill: DHCPConfig: Get new lease with RenewIP If a DHCP process is not running when RenewIP is called, acquire a new lease instead of returning. This allows callers external to shill to avoid having to keep track of whether the IPConfig object has a lease or not. BUG=chromium:318290 TEST=Unit test + manual: Reproduce the issue in crbug.com/318290. In specific, change the IP address to a static IP first and close the configuration panel, then separately switch to custom name servers. Originally-Reviewed-on: https://chromium-review.googlesource.com/177350 (cherry picked from commit abb99ef706a8d6895c5137a5b42a0703fe3fec12) Change-Id: I07bc86b893a502a7fceb86972b04e87928644cd1 Reviewed-on: https://chromium-review.googlesource.com/177762 Reviewed-by: Paul Stewart <pstew@chromium.org> Commit-Queue: Paul Stewart <pstew@chromium.org> Tested-by: Paul Stewart <pstew@chromium.org>

diff --git a/dhcp_config.cc b/dhcp_config.cc
index 0c11115..05ffd33 100644
--- a/dhcp_config.cc
+++ b/dhcp_config.cc

@@ -114,7 +114,7 @@
 bool DHCPConfig::RenewIP() {
   SLOG(DHCP, 2) << __func__ << ": " << device_name();
   if (!pid_) {
-    return false;
+    return Start();
   }
   if (!proxy_.get()) {
     LOG(ERROR) << "Unable to renew IP before acquiring destination.";

diff --git a/dhcp_config_unittest.cc b/dhcp_config_unittest.cc
index 312530d..88adfd2 100644
--- a/dhcp_config_unittest.cc
+++ b/dhcp_config_unittest.cc

@@ -31,6 +31,7 @@
 using testing::_;
 using testing::AnyNumber;
 using testing::ContainsRegex;
+using testing::Mock;
 using testing::Return;
 using testing::SetArgumentPointee;
 using testing::Test;
@@ -604,6 +605,11 @@
 }
 
 TEST_F(DHCPConfigTest, RenewIP) {
+  EXPECT_CALL(*minijail_, RunAndDestroy(_, _, _)).WillOnce(Return(false));
+  config_->pid_ = 0;
+  EXPECT_FALSE(config_->RenewIP());  // Expect a call to Start() if pid_ is 0.
+  Mock::VerifyAndClearExpectations(minijail_.get());
+  EXPECT_CALL(*minijail_, RunAndDestroy(_, _, _)).Times(0);
   EXPECT_TRUE(config_->lease_acquisition_timeout_callback_.IsCancelled());
   config_->pid_ = 456;
   EXPECT_FALSE(config_->RenewIP());  // Expect no crash with NULL proxy.

diff --git a/mock_dhcp_config.h b/mock_dhcp_config.h
index c7de64c..1ce2820 100644
--- a/mock_dhcp_config.h
+++ b/mock_dhcp_config.h

@@ -22,6 +22,7 @@
 
   MOCK_METHOD0(RequestIP, bool());
   MOCK_METHOD1(ReleaseIP, bool(ReleaseReason));
+  MOCK_METHOD0(RenewIP, bool());
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MockDHCPConfig);