Revert "[PA] Add CStringBuilder to replace std::ostringstream used by…

… LogMessage."

This reverts commit 07a88f3.

Reason for revert: breaks MSAN bot
https://ci.chromium.org/ui/p/chromium/builders/ci/Linux%20ChromiumOS%20MSan%20Tests/37602/test-results

[ RUN      ] CStringBuilderTestPA.Char
==313264==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x563432178a89 in partition_alloc::internal::base::strings::CStringBuilder::c_str() ./../../base/allocator/partition_allocator/partition_alloc_base/strings/cstring_builder.cc:145:7
    #1 0x563431d9652c in partition_alloc::internal::base::strings::CStringBuilderTestPA_Char_Test::TestBody() ./../../base/allocator/partition_allocator/partition_alloc_base/strings/cstring_builder_pa_unittest.cc:33:3
    #2 0x5634322101ba in HandleExceptionsInMethodIfSupported<testing::Test, void> ./../../third_party/googletest/src/googletest/src/gtest-internal-inl.h:0:10
    #3 0x5634322101ba in testing::Test::Run() ./../../third_party/googletest/src/googletest/src/gtest.cc:2670:5
    #4 0x563432212ae1 in testing::TestInfo::Run() ./../../third_party/googletest/src/googletest/src/gtest.cc:2849:11
    #5 0x563432214b72 in testing::TestSuite::Run() ./../../third_party/googletest/src/googletest/src/gtest.cc:3008:30
    #6 0x563432242552 in testing::internal::UnitTestImpl::RunAllTests() ./../../third_party/googletest/src/googletest/src/gtest.cc:5866:44
    #7 0x563432241624 in HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool> ./../../third_party/googletest/src/googletest/src/gtest-internal-inl.h:0:10
    #8 0x563432241624 in testing::UnitTest::Run() ./../../third_party/googletest/src/googletest/src/gtest.cc:5440:10
    #9 0x5634329698b0 in RUN_ALL_TESTS ./../../third_party/googletest/src/googletest/include/gtest/gtest.h:2284:73
    #10 0x5634329698b0 in base::TestSuite::Run() ./../../base/test/test_suite.cc:461:16
    #11 0x5634329cc377 in Run ./../../base/functional/callback.h:152:12
    #12 0x5634329cc377 in RunTestSuite ./../../base/test/launcher/unit_test_launcher.cc:179:38
    #13 0x5634329cc377 in base::(anonymous namespace)::LaunchUnitTestsInternal(base::OnceCallback<int ()>, unsigned long, int, unsigned long, bool, base::RepeatingCallback<void ()>, base::OnceCallback<void ()>) ./../../base/test/launcher/unit_test_launcher.cc:240:10
    #14 0x5634329cba64 in base::LaunchUnitTests(int, char**, base::OnceCallback<int ()>, unsigned long) ./../../base/test/launcher/unit_test_launcher.cc:288:10
    #15 0x5634328f3de4 in main ./../../base/test/run_all_unittests.cc:70:10
    #16 0x7f308e293082 in __libc_start_main ??:0:0
    #17 0x56342e6a1349 in _start ??:0:0

  Uninitialized value was created by an allocation of 'builder' in the stack frame
    #0 0x563431d96365 in partition_alloc::internal::base::strings::CStringBuilderTestPA_Char_Test::TestBody() ./../../base/allocator/partition_allocator/partition_alloc_base/strings/cstring_builder_pa_unittest.cc:31:3

SUMMARY: MemorySanitizer: use-of-uninitialized-value (/b/s/w/ir/out/Release/base_unittests+0x43f5a89) (BuildId: 039152aa25034492)
Exiting

Original change's description:
> [PA] Add CStringBuilder to replace std::ostringstream used by LogMessage.
>
> Since std::ostringstream allocates and deallocates memory from heap, c.f. https://source.chromium.org/chromium/chromium/src/+/refs/heads/main:buildtools/third_party/libc++/trunk/src/ios.cpp
>
> std::ostringstream is not available inside memory allocation. Instead
> add CStringBuilder (not resize, fixed buffer size) for LogMessage.
>
> Change-Id: I8051978487acc5fc9b976d6085909b43f81d9d0d
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4744311
> Reviewed-by: Yuki Shiino <[email protected]>
> Commit-Queue: Takashi Sakamoto <[email protected]>
> Cr-Commit-Position: refs/heads/main@{#1179481}

Change-Id: Idb29e3252d9fe67955c0ae25ab46640ebfdae336
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4748189
Auto-Submit: David Roger <[email protected]>
Owners-Override: David Roger <[email protected]>
Commit-Queue: David Roger <[email protected]>
Bot-Commit: Rubber Stamper <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1179539}

base/BUILD.gn

@@ -3802,7 +3802,6 @@ test("base_unittests") {
       "allocator/partition_allocator/partition_alloc_base/logging_pa_unittest.cc",
       "allocator/partition_allocator/partition_alloc_base/rand_util_pa_unittest.cc",
       "allocator/partition_allocator/partition_alloc_base/scoped_clear_last_error_pa_unittest.cc",
-      "allocator/partition_allocator/partition_alloc_base/strings/cstring_builder_pa_unittest.cc",
       "allocator/partition_allocator/partition_alloc_base/strings/safe_sprintf_pa_unittest.cc",
       "allocator/partition_allocator/partition_alloc_base/strings/stringprintf_pa_unittest.cc",
       "allocator/partition_allocator/partition_alloc_base/thread_annotations_pa_unittest.cc",

base/allocator/partition_allocator/BUILD.gn

@@ -376,8 +376,6 @@ source_set("allocator_base") {
     "partition_alloc_base/rand_util.cc",
     "partition_alloc_base/rand_util.h",
     "partition_alloc_base/scoped_clear_last_error.h",
-    "partition_alloc_base/strings/cstring_builder.cc",
-    "partition_alloc_base/strings/cstring_builder.h",
     "partition_alloc_base/strings/safe_sprintf.cc",
     "partition_alloc_base/strings/safe_sprintf.h",
     "partition_alloc_base/strings/stringprintf.cc",