Add granular file tracing.

base/files/file_posix.cc

Index: base/files/file_posix.cc
diff --git a/base/files/file_posix.cc b/base/files/file_posix.cc
index dab9cc25704fcebd4aa7d200ea3ebe5024597adb..4feb4f0bd9ae1e2ec1961b0e948c6328cb58772e 100644
--- a/base/files/file_posix.cc
+++ b/base/files/file_posix.cc
@@ -9,13 +9,13 @@
 #include <sys/stat.h>
 #include <unistd.h>
 
-#include "base/files/file_path.h"
 #include "base/files/file_posix_hooks_internal.h"
 #include "base/logging.h"
 #include "base/metrics/sparse_histogram.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread_restrictions.h"
+#include "base/trace_event/scoped_file_trace.h"
 
 #if defined(OS_ANDROID)
 #include "base/os_compat_android.h"
@@ -181,6 +181,7 @@ PlatformFile File::TakePlatformFile() {
 }
 
 void File::Close() {
+  ScopedFileTrace trace(path_, "Close", 0);
   if (!IsValid())
     return;
 
@@ -210,6 +211,8 @@ int File::Read(int64 offset, char* data, int size) {
   if (size < 0)
     return -1;
 
+  ScopedFileTrace trace(path_, "Read", size);
+
   int bytes_read = 0;
   int rv;
   do {
@@ -230,6 +233,8 @@ int File::ReadAtCurrentPos(char* data, int size) {
   if (size < 0)
     return -1;
 
+  ScopedFileTrace trace(path_, "ReadAtCurrentPos", size);
+
   int bytes_read = 0;
   int rv;
   do {
@@ -246,7 +251,7 @@ int File::ReadAtCurrentPos(char* data, int size) {
 int File::ReadNoBestEffort(int64 offset, char* data, int size) {
   ThreadRestrictions::AssertIOAllowed();
   DCHECK(IsValid());
-
+  ScopedFileTrace trace(path_, "ReadNoBestEffort", size);
   return HANDLE_EINTR(pread(file_.get(), data, size, offset));
 }
 
@@ -256,6 +261,7 @@ int File::ReadAtCurrentPosNoBestEffort(char* data, int size) {
   if (size < 0)
     return -1;
 
+  ScopedFileTrace trace(path_, "ReadAtCurrentPosNoBestEffort", size);
   return HANDLE_EINTR(read(file_.get(), data, size));
 }
 
@@ -269,6 +275,8 @@ int File::Write(int64 offset, const char* data, int size) {
   if (size < 0)
     return -1;
 
+  ScopedFileTrace trace(path_, "Write", size);
+
   int bytes_written = 0;
   int rv;
   do {
@@ -289,6 +297,8 @@ int File::WriteAtCurrentPos(const char* data, int size) {
   if (size < 0)
     return -1;
 
+  ScopedFileTrace trace(path_, "WriteAtCurrentPos", size);
+
   int bytes_written = 0;
   int rv;
   do {
@@ -309,12 +319,15 @@ int File::WriteAtCurrentPosNoBestEffort(const char* data, int size) {
   if (size < 0)
     return -1;
 
+  ScopedFileTrace trace(path_, "WriteAtCurrentPosNoBestEffort", size);
   return HANDLE_EINTR(write(file_.get(), data, size));
 }
 
 int64 File::GetLength() {
   DCHECK(IsValid());
 
+  ScopedFileTrace trace(path_, "GetLength", 0);
+
   stat_wrapper_t file_info;
   if (CallFstat(file_.get(), &file_info))
     return false;
@@ -325,6 +338,8 @@ int64 File::GetLength() {
 bool File::SetLength(int64 length) {
   ThreadRestrictions::AssertIOAllowed();
   DCHECK(IsValid());
+
+  ScopedFileTrace trace(path_, "SetLength", 0);
   return !CallFtruncate(file_.get(), length);
 }
 
@@ -336,12 +351,15 @@ bool File::SetTimes(Time last_access_time, Time last_modified_time) {
   times[0] = last_access_time.ToTimeVal();
   times[1] = last_modified_time.ToTimeVal();
 
+  ScopedFileTrace trace(path_, "SetTimes", 0);
   return !CallFutimes(file_.get(), times);
 }
 
 bool File::GetInfo(Info* info) {
   DCHECK(IsValid());
 
+  ScopedFileTrace trace(path_, "GetInfo", 0);
+
   stat_wrapper_t file_info;
   if (CallFstat(file_.get(), &file_info))
     return false;
@@ -351,10 +369,12 @@ bool File::GetInfo(Info* info) {
 }
 
 File::Error File::Lock() {
+  ScopedFileTrace trace(path_, "Lock", 0);
   return CallFctnlFlock(file_.get(), true);
 }
 
 File::Error File::Unlock() {
+  ScopedFileTrace trace(path_, "Unlock", 0);
   return CallFctnlFlock(file_.get(), false);
 }
 
@@ -362,6 +382,8 @@ File File::Duplicate() {
   if (!IsValid())
     return File();
 
+  ScopedFileTrace trace(path_, "Duplicate", 0);
+
   PlatformFile other_fd = dup(GetPlatformFile());
   if (other_fd == -1)
     return File(OSErrorToFileError(errno));
@@ -454,10 +476,12 @@ void File::MemoryCheckingScopedFD::UpdateChecksum() {
 // NaCl doesn't implement system calls to open files directly.
 #if !defined(OS_NACL)
 // TODO(erikkay): does it make sense to support FLAG_EXCLUSIVE_* here?
-void File::DoInitialize(const FilePath& name, uint32 flags) {
+void File::DoInitialize(uint32 flags) {
   ThreadRestrictions::AssertIOAllowed();
   DCHECK(!IsValid());
 
+  ScopedFileTrace trace(path_, "Initialize", 0);
+
   int open_flags = 0;
   if (flags & FLAG_CREATE)
     open_flags = O_CREAT | O_EXCL;
@@ -509,7 +533,7 @@ void File::DoInitialize(const FilePath& name, uint32 flags) {
   mode |= S_IRGRP | S_IROTH;
 #endif
 
-  int descriptor = HANDLE_EINTR(open(name.value().c_str(), open_flags, mode));
+  int descriptor = HANDLE_EINTR(open(path_.value().c_str(), open_flags, mode));
 
   if (flags & FLAG_OPEN_ALWAYS) {
     if (descriptor < 0) {
@@ -517,7 +541,7 @@ void File::DoInitialize(const FilePath& name, uint32 flags) {
       if (flags & FLAG_EXCLUSIVE_READ || flags & FLAG_EXCLUSIVE_WRITE)
         open_flags |= O_EXCL;   // together with O_CREAT implies O_NOFOLLOW
 
-      descriptor = HANDLE_EINTR(open(name.value().c_str(), open_flags, mode));
+      descriptor = HANDLE_EINTR(open(path_.value().c_str(), open_flags, mode));
       if (descriptor >= 0)
         created_ = true;
     }
@@ -532,7 +556,7 @@ void File::DoInitialize(const FilePath& name, uint32 flags) {
     created_ = true;
 
   if (flags & FLAG_DELETE_ON_CLOSE)
-    unlink(name.value().c_str());
+    unlink(path_.value().c_str());
 
   async_ = ((flags & FLAG_ASYNC) == FLAG_ASYNC);
   error_details_ = FILE_OK;
@@ -544,14 +568,18 @@ void File::DoInitialize(const FilePath& name, uint32 flags) {
 bool File::DoFlush() {
   ThreadRestrictions::AssertIOAllowed();
   DCHECK(IsValid());
+
 #if defined(OS_NACL)
   NOTIMPLEMENTED();  // NaCl doesn't implement fsync.
   return true;
-#elif defined(OS_LINUX) || defined(OS_ANDROID)
+#else
+  ScopedFileTrace trace(path_, "Flush", 0);
+#if defined(OS_LINUX) || defined(OS_ANDROID)
   return !HANDLE_EINTR(fdatasync(file_.get()));
 #else
   return !HANDLE_EINTR(fsync(file_.get()));
-#endif
+#endif  // defined(OS_LINUX) || defined(OS_ANDROID)
+#endif  // defined(OS_NACL)
 }
 
 void File::SetPlatformFile(PlatformFile file) {