Revert of Moved logic for mapping child process FDs for ICU and V8 into child_process_launcher.cc (patchset #20 id:380001 of https://codereview.chromium.org/1182443003/)

Reason for revert:
Adds new static initializers in http://build.chromium.org/p/chromium/buildstatus?builder=Linux%20x64&number=4979

# icu_util.cc cc::VertexShaderQuadAA::VertexShaderQuadAA()
# icu_util.cc base::MemoryMappedFile::MemoryMappedFile()
# icu_util.cc base::i18n::(anonymous namespace)::g_icudtl_region
# icu_util.cc base::i18n::(anonymous namespace)::g_icudtl_mapped_file
# icu_util.cc operator new(unsigned long)

Original issue's description:
> Moved logic for mapping child process FDs for ICU and V8 into child_process_launcher.cc
>
> Used to be defined in each app's ContentBrowserClient, but since
> content/ is the one that receives the FDs, it makes sense that it should
> be the one to send them.
>
> This also removes ChildProcessLauncher::AppendMappedFileCommandLineSwitches
> as it is no longer needed.
>
> BUG=394502
>
> Committed: https://crrev.com/228414fc8870f88f11ada7512e88ea6999890f56
> Cr-Commit-Position: refs/heads/master@{#334702}

TBR=jochen@chromium.org,jam@chromium.org,jungshik@google.com,michaelbai@chromium.org,rmcilroy@chromium.org,thestig@chromium.org,agrieve@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=394502

Review URL: https://codereview.chromium.org/1187213002

Cr-Commit-Position: refs/heads/master@{#334719}

1 files changed, 55 insertions, 72 deletions

diff --git a/gin/v8_initializer.cc b/gin/v8_initializer.cc
index 2ba5106..0568fe7 100644
--- a/gin/v8_initializer.cc
+++ b/gin/v8_initializer.cc
@@ -27,27 +27,10 @@ namespace gin {
 
 namespace {
 
-// None of these globals are ever freed nor closed.
 base::MemoryMappedFile* g_mapped_natives = nullptr;
 base::MemoryMappedFile* g_mapped_snapshot = nullptr;
 
 #if defined(V8_USE_EXTERNAL_STARTUP_DATA)
-
-const base::PlatformFile kInvalidPlatformFile =
-#if defined(OS_WIN)
-    INVALID_HANDLE_VALUE;
-#else
-    -1;
-#endif
-
-// File handles intentionally never closed. Not using File here because its
-// Windows implementation guards against two instances owning the same
-// PlatformFile (which we allow since we know it is never freed).
-base::PlatformFile g_natives_pf = kInvalidPlatformFile;
-base::PlatformFile g_snapshot_pf = kInvalidPlatformFile;
-base::MemoryMappedFile::Region g_natives_region;
-base::MemoryMappedFile::Region g_snapshot_region;
-
 #if !defined(OS_MACOSX)
 const int kV8SnapshotBasePathKey =
 #if defined(OS_ANDROID)
@@ -82,13 +65,13 @@ void GetV8FilePath(const char* file_name, base::FilePath* path_out) {
   DCHECK(!path_out->empty());
 }
 
-static bool MapV8File(base::PlatformFile platform_file,
+static bool MapV8File(base::File file,
                       base::MemoryMappedFile::Region region,
                       base::MemoryMappedFile** mmapped_file_out) {
   DCHECK(*mmapped_file_out == NULL);
   base::MemoryMappedFile* mmapped_file = *mmapped_file_out =
       new base::MemoryMappedFile;
-  if (!mmapped_file->Initialize(base::File(platform_file), region)) {
+  if (!mmapped_file->Initialize(file.Pass(), region)) {
     delete mmapped_file;
     *mmapped_file_out = NULL;
     return false;
@@ -97,8 +80,9 @@ static bool MapV8File(base::PlatformFile platform_file,
   return true;
 }
 
-base::PlatformFile OpenV8File(const char* file_name,
-                              base::MemoryMappedFile::Region* region_out) {
+static bool OpenV8File(const base::FilePath& path,
+                       int flags,
+                       base::File& file) {
   // Re-try logic here is motivated by http://crbug.com/479537
   // for A/V on Windows (https://support.microsoft.com/en-us/kb/316609).
 
@@ -111,16 +95,10 @@ base::PlatformFile OpenV8File(const char* file_name,
     MAX_VALUE
   };
 
-  base::FilePath path;
-  GetV8FilePath(file_name, &path);
-
   OpenV8FileResult result = OpenV8FileResult::FAILED_IN_USE;
-  int flags = base::File::FLAG_OPEN | base::File::FLAG_READ;
-  base::File file;
   for (int attempt = 0; attempt < kMaxOpenAttempts; attempt++) {
     file.Initialize(path, flags);
     if (file.IsValid()) {
-      *region_out = base::MemoryMappedFile::Region::kWholeFile;
       if (attempt == 0) {
         result = OpenV8FileResult::OPENED;
         break;
@@ -140,19 +118,9 @@ base::PlatformFile OpenV8File(const char* file_name,
   UMA_HISTOGRAM_ENUMERATION("V8.Initializer.OpenV8File.Result",
                             result,
                             OpenV8FileResult::MAX_VALUE);
-  return file.TakePlatformFile();
-}
 
-void OpenNativesFileIfNecessary() {
-  if (g_natives_pf == kInvalidPlatformFile) {
-    g_natives_pf = OpenV8File(kNativesFileName, &g_natives_region);
-  }
-}
-
-void OpenSnapshotFileIfNecessary() {
-  if (g_snapshot_pf == kInvalidPlatformFile) {
-    g_snapshot_pf = OpenV8File(kSnapshotFileName, &g_snapshot_region);
-  }
+  return result == OpenV8FileResult::OPENED
+         || result == OpenV8FileResult::OPENED_RETRY;
 }
 
 #if defined(V8_VERIFY_EXTERNAL_STARTUP_DATA)
@@ -195,15 +163,22 @@ enum LoadV8FileResult {
   V8_LOAD_MAX_VALUE
 };
 
-static LoadV8FileResult MapVerify(base::PlatformFile platform_file,
-                                  const base::MemoryMappedFile::Region& region,
+static LoadV8FileResult OpenMapVerify(
+    const char* file_name,
 #if defined(V8_VERIFY_EXTERNAL_STARTUP_DATA)
-                                  const unsigned char* fingerprint,
+    const unsigned char* fingerprint,
 #endif
-                                  base::MemoryMappedFile** mmapped_file_out) {
-  if (platform_file == kInvalidPlatformFile)
+    base::MemoryMappedFile** mmapped_file_out) {
+  base::FilePath path;
+  GetV8FilePath(file_name, &path);
+
+  base::File file;
+  int flags = base::File::FLAG_OPEN | base::File::FLAG_READ;
+
+  if (!OpenV8File(path, flags, file))
     return V8_LOAD_FAILED_OPEN;
-  if (!MapV8File(platform_file, region, mmapped_file_out))
+  if (!MapV8File(file.Pass(), base::MemoryMappedFile::Region::kWholeFile,
+                 mmapped_file_out))
     return V8_LOAD_FAILED_MAP;
 #if defined(V8_VERIFY_EXTERNAL_STARTUP_DATA)
   if (!VerifyV8StartupFile(mmapped_file_out, fingerprint))
@@ -217,14 +192,11 @@ void V8Initializer::LoadV8Snapshot() {
   if (g_mapped_snapshot)
     return;
 
-  OpenSnapshotFileIfNecessary();
-  LoadV8FileResult result = MapVerify(g_snapshot_pf, g_snapshot_region,
+  LoadV8FileResult result = OpenMapVerify(kSnapshotFileName,
 #if defined(V8_VERIFY_EXTERNAL_STARTUP_DATA)
-                                      g_snapshot_fingerprint,
+                                          g_snapshot_fingerprint,
 #endif
-                                      &g_mapped_snapshot);
-  // V8 can't start up without the source of the natives, but it can
-  // start up (slower) without the snapshot.
+                                          &g_mapped_snapshot);
   UMA_HISTOGRAM_ENUMERATION("V8.Initializer.LoadV8Snapshot.Result", result,
                             V8_LOAD_MAX_VALUE);
 }
@@ -233,12 +205,11 @@ void V8Initializer::LoadV8Natives() {
   if (g_mapped_natives)
     return;
 
-  OpenNativesFileIfNecessary();
-  LoadV8FileResult result = MapVerify(g_natives_pf, g_natives_region,
+  LoadV8FileResult result = OpenMapVerify(kNativesFileName,
 #if defined(V8_VERIFY_EXTERNAL_STARTUP_DATA)
-                                      g_natives_fingerprint,
+                                          g_natives_fingerprint,
 #endif
-                                      &g_mapped_natives);
+                                          &g_mapped_natives);
   if (result != V8_LOAD_SUCCESS) {
     LOG(FATAL) << "Couldn't mmap v8 natives data file, status code is "
                << static_cast<int>(result);
@@ -252,7 +223,7 @@ void V8Initializer::LoadV8SnapshotFromFD(base::PlatformFile snapshot_pf,
   if (g_mapped_snapshot)
     return;
 
-  if (snapshot_pf == kInvalidPlatformFile)
+  if (snapshot_pf == reinterpret_cast<base::PlatformFile>(-1))
     return;
 
   base::MemoryMappedFile::Region snapshot_region =
@@ -263,7 +234,7 @@ void V8Initializer::LoadV8SnapshotFromFD(base::PlatformFile snapshot_pf,
   }
 
   LoadV8FileResult result = V8_LOAD_SUCCESS;
-  if (!MapV8File(snapshot_pf, snapshot_region, &g_mapped_snapshot))
+  if (!MapV8File(base::File(snapshot_pf), snapshot_region, &g_mapped_snapshot))
     result = V8_LOAD_FAILED_MAP;
 #if defined(V8_VERIFY_EXTERNAL_STARTUP_DATA)
   if (!VerifyV8StartupFile(&g_mapped_snapshot, g_snapshot_fingerprint))
@@ -280,7 +251,7 @@ void V8Initializer::LoadV8NativesFromFD(base::PlatformFile natives_pf,
   if (g_mapped_natives)
     return;
 
-  CHECK_NE(natives_pf, kInvalidPlatformFile);
+  CHECK_NE(natives_pf, reinterpret_cast<base::PlatformFile>(-1));
 
   base::MemoryMappedFile::Region natives_region =
       base::MemoryMappedFile::Region::kWholeFile;
@@ -289,7 +260,7 @@ void V8Initializer::LoadV8NativesFromFD(base::PlatformFile natives_pf,
         base::MemoryMappedFile::Region(natives_offset, natives_size);
   }
 
-  if (!MapV8File(natives_pf, natives_region, &g_mapped_natives)) {
+  if (!MapV8File(base::File(natives_pf), natives_region, &g_mapped_natives)) {
     LOG(FATAL) << "Couldn't mmap v8 natives data file";
   }
 #if defined(V8_VERIFY_EXTERNAL_STARTUP_DATA)
@@ -300,21 +271,33 @@ void V8Initializer::LoadV8NativesFromFD(base::PlatformFile natives_pf,
 }
 
 // static
-base::PlatformFile V8Initializer::GetOpenNativesFileForChildProcesses(
-    base::MemoryMappedFile::Region* region_out) {
-  OpenNativesFileIfNecessary();
-  *region_out = g_natives_region;
-  return g_natives_pf;
+bool V8Initializer::OpenV8FilesForChildProcesses(
+    base::PlatformFile* natives_fd_out,
+    base::PlatformFile* snapshot_fd_out) {
+  base::FilePath natives_data_path;
+  base::FilePath snapshot_data_path;
+  GetV8FilePath(kNativesFileName, &natives_data_path);
+  GetV8FilePath(kSnapshotFileName, &snapshot_data_path);
+
+  base::File natives_data_file;
+  base::File snapshot_data_file;
+  int file_flags = base::File::FLAG_OPEN | base::File::FLAG_READ;
+
+  bool natives_success =
+      OpenV8File(natives_data_path, file_flags, natives_data_file);
+  if (natives_success) {
+    *natives_fd_out = natives_data_file.TakePlatformFile();
+  }
+  bool snapshot_success =
+      OpenV8File(snapshot_data_path, file_flags, snapshot_data_file);
+  if (snapshot_success) {
+    *snapshot_fd_out = snapshot_data_file.TakePlatformFile();
+  }
+  // We can start up without the snapshot file, but not without the natives.
+  return natives_success;
 }
 
-// static
-base::PlatformFile V8Initializer::GetOpenSnapshotFileForChildProcesses(
-    base::MemoryMappedFile::Region* region_out) {
-  OpenSnapshotFileIfNecessary();
-  *region_out = g_snapshot_region;
-  return g_snapshot_pf;
-}
-#endif  // defined(V8_USE_EXTERNAL_STARTUP_DATA)
+#endif  // V8_USE_EXTERNAL_STARTUP_DATA
 
 // static
 void V8Initializer::Initialize(gin::IsolateHolder::ScriptMode mode) {