Revert of Stack trace symbolization for Chrome sandbox processes. (ht…

…tps://codereview.chromium.org/184273012/)

Reason for revert:
I believe this has broken ProcMapsTest.ParseProcMapsInvalidParameter test in base_unittests, see http://build.chromium.org/p/chromium.webkit/builders/Android%20Tests%20%28dbg%29/builds/18196

Original issue's description:
> Stack trace symbolization for Chrome sandbox processes.
> 
> Patching the POSIX implementation of base::debug::StackTrace to properly
> symbolize stack traces when used in Chrome sandbox processes. The main
> reason symbolization doesn't work today is because sandboxed processes
> cannot open proc/self/maps and the object files that contain the symbols.
> 
> The proposed solution is to open all necessary files before enabling the
> sandbox and then keep their file descriptors around for the duration of
> the sandboxed process.  This cannot be done in  shipping/retail builds
> because it has security implications so for the time being this code will
> run only in DEBUG builds of Chrome.
> 
> Originally, the code review was started under a different account.  For
> more information take a look at: https://codereview.chromium.org/156043003/
> 
> BUG=341966
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=258548

TBR=jamesr@chromium.org,jln@chromium.org,ajwong@chromium.org,rsesek@chromium.org,ivanpe@google.com
NOTREECHECKS=true
NOTRY=true
BUG=341966

Review URL: https://codereview.chromium.org/208363002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@258587 0039d316-1c4b-4281-b951-d872f2087c98

base/debug/proc_maps_linux.cc

@@ -91,7 +91,6 @@ bool ReadProcMaps(std::string* proc_maps) {
 
 bool ParseProcMaps(const std::string& input,
                    std::vector<MappedMemoryRegion>* regions_out) {
-  CHECK(regions_out);
   std::vector<MappedMemoryRegion> regions;
 
   // This isn't async safe nor terribly efficient, but it doesn't need to be at
@@ -102,10 +101,8 @@ bool ParseProcMaps(const std::string& input,
   for (size_t i = 0; i < lines.size(); ++i) {
     // Due to splitting on '\n' the last line should be empty.
     if (i == lines.size() - 1) {
-      if (!lines[i].empty()) {
-        DLOG(WARNING) << "Last line not empty";
+      if (!lines[i].empty())
         return false;
-      }
       break;
     }
 
@@ -128,7 +125,6 @@ bool ParseProcMaps(const std::string& input,
     if (sscanf(line, "%" SCNxPTR "-%" SCNxPTR " %4c %llx %hhx:%hhx %ld %n",
                &region.start, &region.end, permissions, &region.offset,
                &dev_major, &dev_minor, &inode, &path_index) < 7) {
-      DPLOG(WARNING) << "sscanf failed for line: " << line;
       return false;
     }
 

base/debug/proc_maps_linux_unittest.cc

@@ -277,43 +277,5 @@ TEST(ProcMapsTest, InvalidInput) {
   }
 }
 
-TEST(ProcMapsTest, ParseProcMapsInvalidParameter) {
-  // The default style "fast" does not support multi-threaded tests.
-  ::testing::FLAGS_gtest_death_test_style = "threadsafe";
-  ASSERT_DEATH(ParseProcMaps("", NULL), "");
-}
-
-TEST(ProcMapsTest, ParseProcMapsEmptyString) {
-  std::vector<MappedMemoryRegion> regions;
-  EXPECT_TRUE(ParseProcMaps("", &regions));
-  EXPECT_EQ(0ULL, regions.size());
-}
-
-// Testing a couple of remotely possible weird things in the input:
-// - Line ending with \r\n or \n\r.
-// - File name contains quotes.
-// - File name has whitespaces.
-TEST(ProcMapsTest, ParseProcMapsWeirdCorrectInput) {
-  std::vector<MappedMemoryRegion> regions;
-  const std::string kContents =
-    "00400000-0040b000 r-xp 00000000 fc:00 2106562 "
-      "               /bin/cat\r\n"
-    "7f53b7dad000-7f53b7f62000 r-xp 00000000 fc:00 263011 "
-      "       /lib/x86_64-linux-gnu/libc-2.15.so\n\r"
-    "7f53b816d000-7f53b818f000 r-xp 00000000 fc:00 264284 "
-      "        /lib/x86_64-linux-gnu/ld-2.15.so\n"
-    "7fff9c7ff000-7fff9c800000 r-xp 00000000 00:00 0 "
-      "               \"vd so\"\n"
-    "ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 "
-      "               [vsys call]\n";
-  EXPECT_TRUE(ParseProcMaps(kContents, &regions));
-  EXPECT_EQ(5ULL, regions.size());
-  EXPECT_EQ("/bin/cat", regions[0].path);
-  EXPECT_EQ("/lib/x86_64-linux-gnu/libc-2.15.so", regions[1].path);
-  EXPECT_EQ("/lib/x86_64-linux-gnu/ld-2.15.so", regions[2].path);
-  EXPECT_EQ("\"vd so\"", regions[3].path);
-  EXPECT_EQ("[vsys call]", regions[4].path);
-}
-
 }  // namespace debug
 }  // namespace base

base/debug/stack_trace.h

@@ -27,15 +27,6 @@ namespace debug {
 // unit_tests only! This is not thread-safe: only call from main thread.
 BASE_EXPORT bool EnableInProcessStackDumping();
 
-// A different version of EnableInProcessStackDumping that also works for
-// sandboxed processes.  For more details take a look at the description
-// of EnableInProcessStackDumping.
-// Calling this function on Linux opens /proc/self/maps and caches its
-// contents. In DEBUG builds, this function also opens the object files that
-// are loaded in memory and caches their file descriptors (this cannot be
-// done in official builds because it has security implications).
-BASE_EXPORT bool EnableInProcessStackDumpingForSandbox();
-
 // A stacktrace can be helpful in debugging. For example, you can include a
 // stacktrace member in a object (probably around #ifndef NDEBUG) so that you
 // can later see where the given object was created from.