Pull cacheinvalidations code directory into chromium repo.

third_party/cacheinvalidation/src/google/cacheinvalidation/impl/exponential-backoff-delay-generator.cc

Index: third_party/cacheinvalidation/src/google/cacheinvalidation/impl/exponential-backoff-delay-generator.cc
diff --git a/third_party/cacheinvalidation/src/google/cacheinvalidation/impl/exponential-backoff-delay-generator.cc b/third_party/cacheinvalidation/src/google/cacheinvalidation/impl/exponential-backoff-delay-generator.cc
new file mode 100644
index 0000000000000000000000000000000000000000..eac021854985ed93aeeaf616395effa1df2e9596
--- /dev/null
+++ b/third_party/cacheinvalidation/src/google/cacheinvalidation/impl/exponential-backoff-delay-generator.cc
@@ -0,0 +1,40 @@
+// Copyright 2012 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "google/cacheinvalidation/impl/exponential-backoff-delay-generator.h"
+
+namespace invalidation {
+
+TimeDelta ExponentialBackoffDelayGenerator::GetNextDelay() {
+  TimeDelta delay = Scheduler::NoDelay();  // After a reset, delay is zero.
+  if (in_retry_mode) {
+    // We used to multiply the current_max_delay_ by the double, but this
+    // implicitly truncated the double to an integer, which would always be 0.
+    // By converting to and from milliseconds, we avoid this problem.
+    delay = TimeDelta::FromMilliseconds(
+        random_->RandDouble() * current_max_delay_.InMilliseconds());
+
+    // Adjust the max for the next run.
+    TimeDelta max_delay = initial_max_delay_ * max_exponential_factor_;
+    if (current_max_delay_ <= max_delay) {  // Guard against overflow.
+      current_max_delay_ *= 2;
+      if (current_max_delay_ > max_delay) {
+        current_max_delay_ = max_delay;
+      }
+    }
+  }
+  in_retry_mode = true;
+  return delay;
+}
+}