Remove k*Threshold constants that are unused

BUG=None
TEST=try

Change-Id: Ia714c1dce72a9ac13aacc12900cbca11efeac890
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2632565Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Commit-Queue: Yusuke Sato <yusukes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844132}

chromeos/constants/chromeos_switches.cc

@@ -33,10 +33,6 @@ const char kTestCrosGaiaIdMigrationStarted[] = "started";
 
 const char kAggressiveCacheDiscardThreshold[] = "aggressive-cache-discard";
 
-const char kAggressiveTabDiscardThreshold[] = "aggressive-tab-discard";
-
-const char kAggressiveThreshold[] = "aggressive";
-
 // If this flag is passed, failed policy fetches will not cause profile
 // initialization to fail. This is useful for tests because it means that
 // tests don't have to mock out the policy infrastructure.
@@ -162,8 +158,6 @@ const char kChildWallpaperLarge[] = "child-wallpaper-large";
 // non-user-writable JPEG file).
 const char kChildWallpaperSmall[] = "child-wallpaper-small";
 
-const char kConservativeThreshold[] = "conservative";
-
 // Forces CrOS region value.
 const char kCrosRegion[] = "cros-region";
 

chromeos/constants/chromeos_switches.h

@@ -25,9 +25,6 @@ namespace switches {
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
 extern const char kAggressiveCacheDiscardThreshold[];
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
-extern const char kAggressiveTabDiscardThreshold[];
-COMPONENT_EXPORT(CHROMEOS_CONSTANTS) extern const char kAggressiveThreshold[];
-COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
 extern const char kAllowFailedPolicyFetchForTest[];
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS) extern const char kAllowRAInDevMode[];
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS) extern const char kAppAutoLaunched[];
@@ -60,7 +57,6 @@ COMPONENT_EXPORT(CHROMEOS_CONSTANTS) extern const char kArcTosHostForTests[];
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS) extern const char kCellularFirst[];
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS) extern const char kChildWallpaperLarge[];
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS) extern const char kChildWallpaperSmall[];
-COMPONENT_EXPORT(CHROMEOS_CONSTANTS) extern const char kConservativeThreshold[];
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS) extern const char kCrosRegion[];
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS) extern const char kCrosRegionsMode[];
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS) extern const char kCrosRegionsModeHide[];