Add a flag to increase the storage quota for Incognito/Guest profiles

docs/flags.md

@@ -69,6 +69,7 @@ These are also available on the `chrome://flags` page.
   `RemoveClientHints` | Removes client hints (information sent to servers about your system, similar to a user agent).
   `SetIpv6ProbeFalse` | Forces the result of the browser's IPv6 probing (i.e. IPv6 connectivity test) to be unsuccessful. This causes IPv4 addresses to be prioritized over IPv6 addresses. Without this flag, the probing result is set to be successful, which causes IPv6 to be used over IPv4 when possible.
   `SpoofWebGLInfo` | Return generic values for WebGLDebugRendererInfo to remove a potential data leak while preventing potential website breakage.
+  `IncreaseIncognitoStorageQuota` | Makes Incognito and Guest profiles compute the storage quota with the same algorithm that regular profiles use. This makes it harder for websites to detect Incognito mode, but may allow sites to induce heavy memory pressure.
 
 - ### Available only on desktop
 

patches/extra/ungoogled-chromium/add-flag-to-increase-incognito-storage-quota.patch

@@ -0,0 +1,65 @@
+--- a/chrome/browser/ungoogled_flag_entries.h
++++ b/chrome/browser/ungoogled_flag_entries.h
+@@ -144,4 +144,8 @@
+      "Spoof WebGL Info",
+      "Return generic values for WebGLDebugRendererInfo to remove a potential data leak while preventing potential website breakage. ungoogled-chromium flag.",
+      kOsAll, FEATURE_WITH_PARAMS_VALUE_TYPE(blink::features::kSpoofWebGLInfo, kSpoofWebGLChoices, "SpoofWebGLInfo")},
++    {"increase-incognito-storage-quota",
++     "Increases the storage quota for Incognito and Guest profiles",
++     "Makes Incognito and Guest profiles compute the storage quota with the same algorithm that regular profiles use. This makes it harder for websites to detect Incognito mode, but may allow sites to induce heavy memory pressure. ungoogled-chromium flag.",
++     kOsAll, FEATURE_VALUE_TYPE(storage::features::kIncreaseIncognitoStorageQuota)},
+ #endif  // CHROME_BROWSER_UNGOOGLED_FLAG_ENTRIES_H_
+--- a/storage/browser/quota/quota_features.cc
++++ b/storage/browser/quota/quota_features.cc
+@@ -41,5 +41,9 @@ BASE_FEATURE(kStaticStorageQuota,
+              "StaticStorageQuota",
+              base::FEATURE_DISABLED_BY_DEFAULT);
+ 
++BASE_FEATURE(kIncreaseIncognitoStorageQuota,
++             "IncreaseIncognitoStorageQuota",
++             base::FEATURE_DISABLED_BY_DEFAULT);
++
+ }  // namespace features
+ }  // namespace storage
+--- a/storage/browser/quota/quota_features.h
++++ b/storage/browser/quota/quota_features.h
+@@ -23,6 +23,8 @@ extern const base::FeatureParam<double>
+ 
+ COMPONENT_EXPORT(STORAGE_BROWSER) BASE_DECLARE_FEATURE(kStaticStorageQuota);
+ 
++COMPONENT_EXPORT(STORAGE_BROWSER) BASE_DECLARE_FEATURE(kIncreaseIncognitoStorageQuota);
++
+ }  // namespace features
+ 
+ }  // namespace storage
+--- a/storage/browser/quota/quota_settings.cc
++++ b/storage/browser/quota/quota_settings.cc
+@@ -9,6 +9,7 @@
+ #include <memory>
+ #include <utility>
+ 
++#include "base/feature_list.h"
+ #include "base/functional/bind.h"
+ #include "base/no_destructor.h"
+ #include "base/numerics/safe_conversions.h"
+@@ -55,7 +56,8 @@ std::optional<QuotaSettings> CalculateNo
+   base::ScopedBlockingCall scoped_blocking_call(FROM_HERE,
+                                                 base::BlockingType::MAY_BLOCK);
+ 
+-  if (is_incognito) {
++  if (is_incognito &&
++      !base::FeatureList::IsEnabled(features::kIncreaseIncognitoStorageQuota)) {
+     return CalculateIncognitoDynamicSettings(
+         device_info_helper->AmountOfPhysicalMemory());
+   }
+@@ -116,7 +118,9 @@ std::optional<QuotaSettings> CalculateNo
+ 
+   QuotaSettings settings;
+ 
+-  int64_t total = device_info_helper->AmountOfTotalDiskSpace(partition_path);
++  int64_t total =
++      is_incognito ? device_info_helper->AmountOfPhysicalMemory()
++                   : device_info_helper->AmountOfTotalDiskSpace(partition_path);
+   if (total == -1) {
+     LOG(ERROR) << "Unable to compute QuotaSettings.";
+     return std::nullopt;

patches/series

@@ -110,3 +110,4 @@ extra/ungoogled-chromium/disable-chromelabs.patch
 extra/ungoogled-chromium/remove-pac-size-limit.patch
 extra/ungoogled-chromium/enable-certificate-transparency-and-add-flag.patch
 extra/ungoogled-chromium/add-flag-to-spoof-webgl-renderer-info.patch
+extra/ungoogled-chromium/add-flag-to-increase-incognito-storage-quota.patch