Added an experiment for an LRU snapshot cache.

ios/chrome/browser/chrome_switches.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ios/chrome/browser/chrome_switches.h"
 
 namespace switches {
 
 // -----------------------------------------------------------------------------
 // When commenting your switch, please use the same voice as surrounding
@@ skipping 24 matching lines @@
 
 // Disables NTP favicons.
 const char kDisableNTPFavicons[] = "disable-ntp-favicons";
 
 // Disable auto-reload of error pages if offline.
 const char kDisableOfflineAutoReload[] = "disable-offline-auto-reload";
 
 // Disables the tab switcher.
 const char kDisableTabSwitcher[] = "disable-tab-switcher";
 
+// Disable the snapshots lru cache.
+const char kDisableLRUSnapshotCache[] = "disable-lru-snapshot-cache";
+
 // Enables Contextual Search.
 const char kEnableContextualSearch[] = "enable-contextual-search";
 
 // Enable the experimental Credential Manager JavaScript API.
 const char kEnableCredentialManagerAPI[] = "enable-credential-manager-api";
 
 // Enables a workaround for fast inset updates for UIWebView.scrollView.
 const char kEnableIOSFastWebScrollViewInsets[] =
     "enable-fast-web-scroll-view-insets";
 
@@ skipping 13 matching lines @@
 
 // Enable auto-reload of error pages if offline.
 const char kEnableOfflineAutoReload[] = "enable-offline-auto-reload";
 
 // Enables context-sensitive reader mode button in the toolbar.
 const char kEnableReaderModeToolbarIcon[] = "enable-reader-mode-toolbar-icon";
 
 // Enables the tab switcher.
 const char kEnableTabSwitcher[] = "enable-tab-switcher";
 
+// Enables the snapshot lru cache.
+const char kEnableLRUSnapshotCache[] = "enable-lru-snapshot-cache";
+
 // Enables the recording of metrics reports but disables reporting. In contrast
 // to kDisableMetrics, this executes all the code that a normal client would
 // use for reporting, except the report is dropped rather than sent to the
 // server. This is useful for finding issues in the metrics code during UI and
 // performance tests.
 const char kIOSMetricsRecordingOnly[] = "metrics-recording-only";
 
 // A string used to override the default user agent with a custom one.
 const char kUserAgent[] = "user-agent";
 
 }  // namespace switches