Remove deprecated chrome://flags

This is about the chrome flags:
 - disable-pushstate-throttle
 - disable-ipc-flooding-protection

They have previously been deprecated. This patch remove them.
It is still possible to use them with the command line switches.

See also:
 - https://chromium-review.googlesource.com/c/chromium/src/+/1268016
 - https://chromium-review.googlesource.com/c/chromium/src/+/1341526

Bug: 882238
Change-Id: I296e863c63070e8a61ed31babc9276a6e6982e17
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2007819Reviewed-by: Camille Lamy <clamy@chromium.org>
Commit-Queue: Arthur Sonzogni <arthursonzogni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#733367}

chrome/browser/about_flags.cc

@@ -1595,14 +1595,6 @@ const FeatureEntry kFeatureEntries[] = {
      flag_descriptions::kHistoryManipulationIntervention,
      flag_descriptions::kHistoryManipulationInterventionDescription, kOsAll,
      FEATURE_VALUE_TYPE(features::kHistoryManipulationIntervention)},
-    {"disable-pushstate-throttle",
-     flag_descriptions::kDisablePushStateThrottleName,
-     flag_descriptions::kDisablePushStateThrottleDescription, kOsAll,
-     SINGLE_VALUE_TYPE(switches::kDisablePushStateThrottle)},
-    {"disable-ipc-flooding-protection",
-     flag_descriptions::kDisableIpcFloodingProtectionName,
-     flag_descriptions::kDisableIpcFloodingProtectionDescription, kOsAll,
-     SINGLE_VALUE_TYPE(switches::kDisableIpcFloodingProtection)},
 #if defined(OS_ANDROID)
     {"contextual-search-definitions",
      flag_descriptions::kContextualSearchDefinitionsName,

chrome/browser/flag-metadata.json

@@ -768,12 +768,6 @@
     "owners": [ "ccameron" ],
     "expiry_milestone": 77
   },
-  {
-    // See https://crbug.com/882238.
-    "name": "disable-ipc-flooding-protection",
-    "owners": [ "arthursonzogni@chromium.org", "palmer@chromium.org" ],
-    "expiry_milestone": 76
-  },
   {
     "name": "disable-javascript-harmony-shipping",
     "owners": [ "adamk", "hablich" ],
@@ -793,12 +787,6 @@
       "quickoffice-chrome-eng@google.com" ],
     "expiry_milestone": 88
   },
-  {
-    // See https://crbug.com/882238.
-    "name": "disable-pushstate-throttle",
-    "owners": [ "arthursonzogni@chromium.org", "palmer@chromium.org" ],
-    "expiry_milestone": 76
-  },
   {
     "name": "disable-threaded-scrolling",
     "owners": [ "bokan", "input-dev" ],

chrome/browser/flag_descriptions.cc

@@ -465,21 +465,6 @@ const char kDisableBestEffortTasksDescription[] =
     "user data to disk, cleaning caches, reporting metrics or updating "
     "components won't be performed until shutdown.";
 
-const char kDisableIpcFloodingProtectionName[] =
-    "Disable IPC flooding protection";
-const char kDisableIpcFloodingProtectionDescription[] =
-    "Some javascript code can flood the inter process communication system. "
-    "This protection limits the rate (calls/seconds) at which theses function "
-    "can be used. This flag disables the protection. This flag is deprecated "
-    "and will be removed in Chrome 76. Use the switch "
-    "--disable-ipc-flooding-protection instead.";
-
-const char kDisablePushStateThrottleName[] = "Disable pushState throttling";
-const char kDisablePushStateThrottleDescription[] =
-    "Disables throttling of history.pushState and history.replaceState method "
-    "calls. This flag is deprecated and will be removed in Chrome 76. Use the "
-    "switch --disable-ipc-flooding-protection instead.";
-
 const char kDisallowDocWrittenScriptsUiName[] =
     "Block scripts loaded via document.write";
 const char kDisallowDocWrittenScriptsUiDescription[] =

chrome/browser/flag_descriptions.h

@@ -297,12 +297,6 @@ extern const char kDisableAudioForDesktopShareDescription[];
 extern const char kDisableBestEffortTasksName[];
 extern const char kDisableBestEffortTasksDescription[];
 
-extern const char kDisableIpcFloodingProtectionName[];
-extern const char kDisableIpcFloodingProtectionDescription[];
-
-extern const char kDisablePushStateThrottleName[];
-extern const char kDisablePushStateThrottleDescription[];
-
 extern const char kDisallowDocWrittenScriptsUiName[];
 extern const char kDisallowDocWrittenScriptsUiDescription[];