diff --git a/constants.cc b/constants.cc
index 3064c40..0bc95f7 100644
--- a/constants.cc
+++ b/constants.cc
@@ -31,6 +31,7 @@
 const char kPrefsTotalBytesDownloaded[] = "total-bytes-downloaded";
 const char kPrefsUpdateCheckCount[] = "update-check-count";
 const char kPrefsUpdateCheckResponseHash[] = "update-check-response-hash";
+const char kPrefsUpdateDurationUptime[] = "update-duration-uptime";
 const char kPrefsUpdateFirstSeenAt[] = "update-first-seen-at";
 const char kPrefsUpdateServerCertificate[] = "update-server-cert";
 const char kPrefsUpdateStateNextDataOffset[] = "update-state-next-data-offset";
@@ -39,8 +40,8 @@
 const char kPrefsUpdateStateSignatureBlob[] = "update-state-signature-blob";
 const char kPrefsUpdateStateSignedSHA256Context[] =
     "update-state-signed-sha-256-context";
-const char kPrefsWallClockWaitPeriod[] = "wall-clock-wait-period";
 const char kPrefsUpdateTimestampStart[] = "update-timestamp-start";
-const char kPrefsUpdateDurationUptime[] = "update-duration-uptime";
+const char kPrefsUrlSwitchCount[] = "url-switch-count";
+const char kPrefsWallClockWaitPeriod[] = "wall-clock-wait-period";
 
 }
diff --git a/constants.h b/constants.h
index b2c1de2..3b8a918 100644
--- a/constants.h
+++ b/constants.h
@@ -32,6 +32,7 @@
 extern const char kPrefsTotalBytesDownloaded[];
 extern const char kPrefsUpdateCheckCount[];
 extern const char kPrefsUpdateCheckResponseHash[];
+extern const char kPrefsUpdateDurationUptime[];
 extern const char kPrefsUpdateFirstSeenAt[];
 extern const char kPrefsUpdateServerCertificate[];
 extern const char kPrefsUpdateStateNextDataOffset[];
@@ -39,9 +40,9 @@
 extern const char kPrefsUpdateStateSHA256Context[];
 extern const char kPrefsUpdateStateSignatureBlob[];
 extern const char kPrefsUpdateStateSignedSHA256Context[];
-extern const char kPrefsWallClockWaitPeriod[];
 extern const char kPrefsUpdateTimestampStart[];
-extern const char kPrefsUpdateDurationUptime[];
+extern const char kPrefsUrlSwitchCount[];
+extern const char kPrefsWallClockWaitPeriod[];
 
 // A download source is any combination of protocol and server (that's of
 // interest to us when looking at UMA metrics) using which we may download
diff --git a/mock_payload_state.h b/mock_payload_state.h
index c32ff78..fe744de 100644
--- a/mock_payload_state.h
+++ b/mock_payload_state.h
@@ -31,6 +31,7 @@
   MOCK_METHOD0(GetPayloadAttemptNumber, uint32_t());
   MOCK_METHOD0(GetUrlIndex, uint32_t());
   MOCK_METHOD0(GetUrlFailureCount, uint32_t());
+  MOCK_METHOD0(GetUrlSwitchCount, uint32_t());
   MOCK_METHOD0(GetBackoffExpiryTime, base::Time());
   MOCK_METHOD0(GetUpdateDuration, base::TimeDelta());
   MOCK_METHOD0(GetUpdateDurationUptime, base::TimeDelta());
diff --git a/payload_state.cc b/payload_state.cc
index bdc9bb4..2a26722 100644
--- a/payload_state.cc
+++ b/payload_state.cc
@@ -34,7 +34,8 @@
     : prefs_(NULL),
       payload_attempt_number_(0),
       url_index_(0),
-      url_failure_count_(0) {
+      url_failure_count_(0),
+      url_switch_count_(0) {
  for (int i = 0; i <= kNumDownloadSources; i++)
   total_bytes_downloaded_[i] = current_bytes_downloaded_[i] = 0;
 }
@@ -46,6 +47,7 @@
   LoadPayloadAttemptNumber();
   LoadUrlIndex();
   LoadUrlFailureCount();
+  LoadUrlSwitchCount();
   LoadBackoffExpiryTime();
   LoadUpdateTimestampStart();
   // The LoadUpdateDurationUptime() method relies on LoadUpdateTimestampStart()
@@ -132,6 +134,7 @@
   CalculateUpdateDurationUptime();
   SetUpdateTimestampEnd(Time::Now());
   ReportBytesDownloadedMetrics();
+  ReportUpdateUrlSwitchesMetric();
 }
 
 void PayloadState::UpdateFailed(ActionExitCode error) {
@@ -304,6 +307,10 @@
     IncrementPayloadAttemptNumber();
   }
 
+  // If we have multiple URLs, record that we just switched to another one
+  if (GetNumUrls() > 1)
+    SetUrlSwitchCount(url_switch_count_ + 1);
+
   // Whenever we update the URL index, we should also clear the URL failure
   // count so we can start over fresh for the new URL.
   SetUrlFailureCount(0);
@@ -415,10 +422,24 @@
   }
 }
 
+void PayloadState::ReportUpdateUrlSwitchesMetric() {
+  string metric = "Installer.UpdateURLSwitches";
+  int value = static_cast<int>(url_switch_count_);
+
+  LOG(INFO) << "Uploading " << value << " (count) for metric " <<  metric;
+  system_state_->metrics_lib()->SendToUMA(
+       metric,
+       value,
+       0,    // min value
+       100,  // max value
+       kNumDefaultUmaBuckets);
+}
+
 void PayloadState::ResetPersistedState() {
   SetPayloadAttemptNumber(0);
   SetUrlIndex(0);
   SetUrlFailureCount(0);
+  SetUrlSwitchCount(0);
   UpdateBackoffExpiryTime(); // This will reset the backoff expiry time.
   SetUpdateTimestampStart(Time::Now());
   SetUpdateTimestampEnd(Time()); // Set to null time
@@ -521,6 +542,17 @@
   UpdateCurrentDownloadSource();
 }
 
+void PayloadState::LoadUrlSwitchCount() {
+  SetUrlSwitchCount(GetPersistedValue(kPrefsUrlSwitchCount));
+}
+
+void PayloadState::SetUrlSwitchCount(uint32_t url_switch_count) {
+  CHECK(prefs_);
+  url_switch_count_ = url_switch_count;
+  LOG(INFO) << "URL Switch Count = " << url_switch_count_;
+  prefs_->SetInt64(kPrefsUrlSwitchCount, url_switch_count_);
+}
+
 void PayloadState::LoadUrlFailureCount() {
   SetUrlFailureCount(GetPersistedValue(kPrefsCurrentUrlFailureCount));
 }
diff --git a/payload_state.h b/payload_state.h
index b34422f..5427c74 100644
--- a/payload_state.h
+++ b/payload_state.h
@@ -56,6 +56,10 @@
     return url_failure_count_;
   }
 
+  virtual inline uint32_t GetUrlSwitchCount() {
+    return url_switch_count_;
+  }
+
   virtual inline base::Time GetBackoffExpiryTime() {
     return backoff_expiry_time_;
   }
@@ -80,7 +84,8 @@
   // Advances the current URL index to the next available one. If all URLs have
   // been exhausted during the current payload download attempt (as indicated
   // by the payload attempt number), then it will increment the payload attempt
-  // number and wrap around again with the first URL in the list.
+  // number and wrap around again with the first URL in the list. This also
+  // updates the URL switch count, if needed.
   void IncrementUrlIndex();
 
   // Increments the failure count of the current URL. If the configured max
@@ -104,6 +109,9 @@
   // Reports the various metrics related to the number of bytes downloaded.
   void ReportBytesDownloadedMetrics();
 
+  // Reports the metric related to number of URL switches.
+  void ReportUpdateUrlSwitchesMetric();
+
   // Resets all the persisted state values which are maintained relative to the
   // current response signature. The response signature itself is not reset.
   void ResetPersistedState();
@@ -153,6 +161,12 @@
   // restart.
   void SetUrlFailureCount(uint32_t url_failure_count);
 
+  // Sets |url_switch_count_| to the given value and persists the value.
+  void SetUrlSwitchCount(uint32_t url_switch_count);
+
+  // Initializes |url_switch_count_| from the persisted stae.
+  void LoadUrlSwitchCount();
+
   // Initializes the backoff expiry time from the persisted state.
   void LoadBackoffExpiryTime();
 
@@ -253,6 +267,9 @@
   // persisted so we resume from the same value in case of a process restart.
   int64_t url_failure_count_;
 
+  // The number of times we've switched URLs.
+  int32_t url_switch_count_;
+
   // The current download source based on the current URL. This value is
   // not persisted as it can be recomputed everytime we update the URL.
   // We're storing this so as not to recompute this on every few bytes of
diff --git a/payload_state_interface.h b/payload_state_interface.h
index 133124d..76b847a 100644
--- a/payload_state_interface.h
+++ b/payload_state_interface.h
@@ -72,6 +72,10 @@
   // Returns the current URL's failure count.
   virtual uint32_t GetUrlFailureCount() = 0;
 
+  // Returns the total number of times a new URL has been switched to
+  // for the current response.
+  virtual uint32_t GetUrlSwitchCount() = 0;
+
   // Returns the expiry time for the current backoff period.
   virtual base::Time GetBackoffExpiryTime() = 0;
 
diff --git a/payload_state_unittest.cc b/payload_state_unittest.cc
index ffd1b27..a0f5a42 100644
--- a/payload_state_unittest.cc
+++ b/payload_state_unittest.cc
@@ -114,6 +114,7 @@
   EXPECT_EQ(expected_response_sign, stored_response_sign);
   EXPECT_EQ(0, payload_state.GetUrlIndex());
   EXPECT_EQ(0, payload_state.GetUrlFailureCount());
+  EXPECT_EQ(0, payload_state.GetUrlSwitchCount());
 }
 
 TEST(PayloadStateTest, SetResponseWorksWithSingleUrl) {
@@ -158,6 +159,7 @@
   EXPECT_EQ(expected_response_sign, stored_response_sign);
   EXPECT_EQ(0, payload_state.GetUrlIndex());
   EXPECT_EQ(0, payload_state.GetUrlFailureCount());
+  EXPECT_EQ(0, payload_state.GetUrlSwitchCount());
 }
 
 TEST(PayloadStateTest, SetResponseWorksWithMultipleUrls) {
@@ -200,6 +202,7 @@
   EXPECT_EQ(expected_response_sign, stored_response_sign);
   EXPECT_EQ(0, payload_state.GetUrlIndex());
   EXPECT_EQ(0, payload_state.GetUrlFailureCount());
+  EXPECT_EQ(0, payload_state.GetUrlSwitchCount());
 }
 
 TEST(PayloadStateTest, CanAdvanceUrlIndexCorrectly) {
@@ -244,6 +247,9 @@
   // Verify that on the next error, it again advances to 1.
   payload_state.UpdateFailed(error);
   EXPECT_EQ(1, payload_state.GetUrlIndex());
+
+  // Verify that we switched URLs three times
+  EXPECT_EQ(3, payload_state.GetUrlSwitchCount());
 }
 
 TEST(PayloadStateTest, NewResponseResetsPayloadState) {
@@ -260,6 +266,7 @@
   ActionExitCode error = kActionCodeDownloadMetadataSignatureMismatch;
   payload_state.UpdateFailed(error);
   EXPECT_EQ(1, payload_state.GetUrlIndex());
+  EXPECT_EQ(1, payload_state.GetUrlSwitchCount());
 
   // Now, slightly change the response and set it again.
   SetupPayloadStateWith2Urls("Hash8225", &payload_state, &response);
@@ -267,6 +274,7 @@
   // Make sure the url index was reset to 0 because of the new response.
   EXPECT_EQ(0, payload_state.GetUrlIndex());
   EXPECT_EQ(0, payload_state.GetUrlFailureCount());
+  EXPECT_EQ(0, payload_state.GetUrlSwitchCount());
   EXPECT_EQ(0,
             payload_state.GetCurrentBytesDownloaded(kDownloadSourceHttpServer));
   EXPECT_EQ(0,
@@ -327,18 +335,21 @@
   EXPECT_EQ(0, payload_state.GetPayloadAttemptNumber());
   EXPECT_EQ(1, payload_state.GetUrlIndex());
   EXPECT_EQ(0, payload_state.GetUrlFailureCount());
+  EXPECT_EQ(1, payload_state.GetUrlSwitchCount());
 
   // This should advance the failure count only.
   payload_state.UpdateFailed(kActionCodeDownloadTransferError);
   EXPECT_EQ(0, payload_state.GetPayloadAttemptNumber());
   EXPECT_EQ(1, payload_state.GetUrlIndex());
   EXPECT_EQ(1, payload_state.GetUrlFailureCount());
+  EXPECT_EQ(1, payload_state.GetUrlSwitchCount());
 
   // This should advance the failure count only.
   payload_state.UpdateFailed(kActionCodeDownloadTransferError);
   EXPECT_EQ(0, payload_state.GetPayloadAttemptNumber());
   EXPECT_EQ(1, payload_state.GetUrlIndex());
   EXPECT_EQ(2, payload_state.GetUrlFailureCount());
+  EXPECT_EQ(1, payload_state.GetUrlSwitchCount());
 
   // This should advance the URL index as we've reached the
   // max failure count and reset the failure count for the new URL index.
@@ -348,6 +359,7 @@
   EXPECT_EQ(1, payload_state.GetPayloadAttemptNumber());
   EXPECT_EQ(0, payload_state.GetUrlIndex());
   EXPECT_EQ(0, payload_state.GetUrlFailureCount());
+  EXPECT_EQ(2, payload_state.GetUrlSwitchCount());
   EXPECT_TRUE(payload_state.ShouldBackoffDownload());
 
   // This should advance the URL index.
@@ -355,6 +367,7 @@
   EXPECT_EQ(1, payload_state.GetPayloadAttemptNumber());
   EXPECT_EQ(1, payload_state.GetUrlIndex());
   EXPECT_EQ(0, payload_state.GetUrlFailureCount());
+  EXPECT_EQ(3, payload_state.GetUrlSwitchCount());
   EXPECT_TRUE(payload_state.ShouldBackoffDownload());
 
   // This should advance the URL index and payload attempt number due to
@@ -363,6 +376,7 @@
   EXPECT_EQ(2, payload_state.GetPayloadAttemptNumber());
   EXPECT_EQ(0, payload_state.GetUrlIndex());
   EXPECT_EQ(0, payload_state.GetUrlFailureCount());
+  EXPECT_EQ(4, payload_state.GetUrlSwitchCount());
   EXPECT_TRUE(payload_state.ShouldBackoffDownload());
 
   // This HTTP error code should only increase the failure count.
@@ -371,6 +385,7 @@
   EXPECT_EQ(2, payload_state.GetPayloadAttemptNumber());
   EXPECT_EQ(0, payload_state.GetUrlIndex());
   EXPECT_EQ(1, payload_state.GetUrlFailureCount());
+  EXPECT_EQ(4, payload_state.GetUrlSwitchCount());
   EXPECT_TRUE(payload_state.ShouldBackoffDownload());
 
   // And that failure count should be reset when we download some bytes
@@ -379,6 +394,7 @@
   EXPECT_EQ(2, payload_state.GetPayloadAttemptNumber());
   EXPECT_EQ(0, payload_state.GetUrlIndex());
   EXPECT_EQ(0, payload_state.GetUrlFailureCount());
+  EXPECT_EQ(4, payload_state.GetUrlSwitchCount());
   EXPECT_TRUE(payload_state.ShouldBackoffDownload());
 
   // Now, slightly change the response and set it again.
@@ -388,6 +404,7 @@
   EXPECT_EQ(0, payload_state.GetPayloadAttemptNumber());
   EXPECT_EQ(0, payload_state.GetUrlIndex());
   EXPECT_EQ(0, payload_state.GetUrlFailureCount());
+  EXPECT_EQ(0, payload_state.GetUrlSwitchCount());
   EXPECT_FALSE(payload_state.ShouldBackoffDownload());
 }
 
@@ -421,6 +438,7 @@
   EXPECT_EQ(1, payload_state.GetPayloadAttemptNumber());
   EXPECT_EQ(0, payload_state.GetUrlIndex());
   EXPECT_EQ(0, payload_state.GetUrlFailureCount());
+  EXPECT_EQ(0, payload_state.GetUrlSwitchCount());
 }
 
 TEST(PayloadStateTest, SetResponseResetsInvalidUrlIndex) {
@@ -439,6 +457,7 @@
   EXPECT_EQ(1, payload_state.GetPayloadAttemptNumber());
   EXPECT_EQ(1, payload_state.GetUrlIndex());
   EXPECT_EQ(1, payload_state.GetUrlFailureCount());
+  EXPECT_EQ(1, payload_state.GetUrlSwitchCount());
 
   // Now, simulate a corrupted url index on persisted store which gets
   // loaded when update_engine restarts. Using a different prefs object
@@ -453,6 +472,8 @@
       .WillRepeatedly(DoAll(SetArgumentPointee<1>(2), Return(true)));
   EXPECT_CALL(*prefs2, GetInt64(kPrefsCurrentUrlFailureCount, _))
     .Times(AtLeast(1));
+  EXPECT_CALL(*prefs2, GetInt64(kPrefsUrlSwitchCount, _))
+    .Times(AtLeast(1));
 
   // Note: This will be a different payload object, but the response should
   // have the same hash as before so as to not trivially reset because the
@@ -466,6 +487,7 @@
   EXPECT_EQ(0, payload_state.GetPayloadAttemptNumber());
   EXPECT_EQ(0, payload_state.GetUrlIndex());
   EXPECT_EQ(0, payload_state.GetUrlFailureCount());
+  EXPECT_EQ(0, payload_state.GetUrlSwitchCount());
 }
 
 TEST(PayloadStateTest, NoBackoffForDeltaPayloads) {
@@ -628,6 +650,9 @@
   EXPECT_CALL(*mock_system_state.mock_metrics_lib(), SendToUMA(
       "Installer.TotalMBsDownloadedFromHttpsServer",
       https_total / kNumBytesInOneMiB, _, _, _));
+  EXPECT_CALL(*mock_system_state.mock_metrics_lib(), SendToUMA(
+      "Installer.UpdateURLSwitches",
+      2, _, _, _));
 
   payload_state.UpdateSucceeded();