Android: Remove ignore_elf32_limitations GN arg and related assert

Building libmonochrome.so with symbol_level=2 results in a 3.6GB file,
which is under the 4GB size of concern.

I'm also not sure if there is still a 4GB limit. The assert and bug were
added when we still used gold linker.

Bug: 1122182, 648948
Change-Id: Ia88041ca4c628f0c5a4fa32c3870dc966f71f19a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3251520
Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Owners-Override: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Hans Wennborg <hans@chromium.org>
Cr-Commit-Position: refs/heads/main@{#935964}

build/config/compiler/BUILD.gn

@@ -2385,19 +2385,15 @@ config("minimal_symbols") {
 
     ldflags = []
     if (is_android && is_clang) {
-      # Android defaults to symbol_level=1 builds in production builds
-      # (https://crbug.com/648948), but clang, unlike gcc, doesn't emit
-      # DW_AT_linkage_name in -g1 builds. -fdebug-info-for-profiling enables
-      # that (and a bunch of other things we don't need), so that we get
-      # qualified names in stacks.
+      # Android defaults to symbol_level=1 builds, but clang, unlike gcc,
+      # doesn't emit DW_AT_linkage_name in -g1 builds.
+      # -fdebug-info-for-profiling enables that (and a bunch of other things we
+      # don't need), so that we get qualified names in stacks.
       # TODO(thakis): Consider making clang emit DW_AT_linkage_name in -g1 mode;
       #               failing that consider doing this on non-Android too.
       cflags += [ "-fdebug-info-for-profiling" ]
     }
 
-    # Note: debug_fission is no-op with symbol_level=1 since all -g1 debug_info
-    # will stay in the executable.
-
     asmflags = cflags
   }
   rustflags = [ "-Cdebuginfo=1" ]

build/config/compiler/compiler.gni

@@ -264,8 +264,7 @@ if (use_debug_fission == "default") {
 assert(symbol_level >= -1 && symbol_level <= 2, "Invalid symbol_level")
 if (symbol_level == -1) {
   if (is_android && !is_component_build && !use_debug_fission) {
-    # Reduce symbol level when it will cause invalid elf files to be created
-    # (due to file size). https://crbug.com/648948.
+    # Prefer faster & smaller release builds.
     symbol_level = 1
   } else if (is_chromeos_device) {
     # Use lower symbol level in Simple Chrome build for faster link time.
@@ -311,15 +310,3 @@ if (forbid_non_component_debug_builds) {
           is_component_build || !is_debug || is_ios || use_debug_fission,
       "Can't do non-component debug builds at symbol_level=2 without use_debug_fission=true")
 }
-
-# Assert that the configuration isn't going to hit https://crbug.com/648948.
-# An exception is made when target_os == "chromeos" as we only use the Android
-# toolchain there to build relatively small binaries.
-assert(
-    ignore_elf32_limitations || !is_android || target_os == "chromeos" ||
-        is_component_build || symbol_level < 2 || use_debug_fission ||
-        (android_64bit_target_cpu && skip_secondary_abi_for_cq),
-    "Android 32-bit non-component builds without DWARF Fission cannot " +
-        "have symbol_level=2 due to 4GiB file size limit, see " +
-        "https://crbug.com/648948. " + "If you really want to try this out, " +
-        "set ignore_elf32_limitations=true.")

build_overrides/build.gni

@@ -52,13 +52,6 @@ declare_args() {
 # ubsan_security_ignorelist_path = "path/to/ubsan/security_ignorelist.txt"
 # cfi_ignorelist_path = "path/to/cfi/ignores.txt"
 
-declare_args() {
-  # Android 32-bit non-component, non-clang builds cannot have symbol_level=2
-  # due to 4GiB file size limit, see https://crbug.com/648948.
-  # Set this flag to true to skip the assertion.
-  ignore_elf32_limitations = false
-}
-
 if (host_os == "mac" || is_apple) {
   # Needed for is_apple when targeting macOS or iOS, independent of host.
   # Needed for host_os=="mac" for running host tool such as gperf in blink

components/cronet/tools/cr_cronet.py

@@ -108,7 +108,7 @@ def get_default_gn_args(target_os, is_release):
       'disable_brotli_filter=false '
       'is_component_build=false '
       'use_crash_key_stubs=true '
-      'ignore_elf32_limitations=true use_partition_alloc=false '
+      'use_partition_alloc=false '
       'include_transport_security_state_preload_list=false ') + use_goma()
   if (is_release):
     gn_args += 'is_debug=false is_official_build=true '