Fix ThreadChecker to use Locks and not use scoped_ptr.

It needs to synchronize its checks, since in order to assert correctly, it needs to make sure the thread id is synchronized on all threads.
It doesn't need scoped_ptr.  It was trying to use NULL to catch invalid thread ids.  0 is already assumed to be invalid (see base::Thread's use).
Eliminating scoped_ptr fixes a valgrind/heapcheck issue where they don't follow LazyInstance objects' member pointers.  So they think the ThreadChecker's member variable is leaked, even though the global object still has a pointer to it.
Removing the scoped_ptr.h caused a bunch of other lame files to fail to compile.  I had to fix those places.  #include what you use please :(

TBR=levin (I want to green the memory bots)
BUG=none
TEST=none

Review URL: http://codereview.chromium.org/5180006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@66915 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 26 insertions, 17 deletions

diff --git a/base/platform_thread.h b/base/platform_thread.h
index e330422..43bf298 100644
--- a/base/platform_thread.h
+++ b/base/platform_thread.h
@@ -34,9 +34,19 @@ typedef pid_t PlatformThreadId;
 #endif
 #endif
 
+const PlatformThreadId kInvalidThreadId = 0;
+
 // A namespace for low-level thread functions.
 class PlatformThread {
  public:
+  // Implement this interface to run code on a background thread.  Your
+  // ThreadMain method will be called on the newly created thread.
+  class Delegate {
+   public:
+    virtual ~Delegate() {}
+    virtual void ThreadMain() = 0;
+  };
+
   // Gets the current thread id, which may be useful for logging purposes.
   static PlatformThreadId CurrentId();
 
@@ -49,14 +59,6 @@ class PlatformThread {
   // Sets the thread name visible to a debugger.  This has no effect otherwise.
   static void SetName(const char* name);
 
-  // Implement this interface to run code on a background thread.  Your
-  // ThreadMain method will be called on the newly created thread.
-  class Delegate {
-   public:
-    virtual ~Delegate() {}
-    virtual void ThreadMain() = 0;
-  };
-
   // Creates a new thread.  The |stack_size| parameter can be 0 to indicate
   // that the default stack size should be used.  Upon success,
   // |*thread_handle| will be assigned a handle to the newly created thread,
diff --git a/base/thread.h b/base/thread.h
index 572eb8a..fc542f0 100644
--- a/base/thread.h
+++ b/base/thread.h
@@ -126,8 +126,8 @@ class Thread : PlatformThread::Delegate {
   PlatformThreadId thread_id() const { return thread_id_; }
 
   // Returns true if the thread has been started, and not yet stopped.
-  // When a thread is running, the thread_id_ is non-zero.
-  bool IsRunning() const { return thread_id_ != 0; }
+  // When a thread is running, |thread_id_| is a valid id.
+  bool IsRunning() const { return thread_id_ != kInvalidThreadId; }
 
  protected:
   // Called just prior to starting the message loop
diff --git a/base/thread_checker.cc b/base/thread_checker.cc
index 394a90a..52f9847 100644
--- a/base/thread_checker.cc
+++ b/base/thread_checker.cc
@@ -7,7 +7,7 @@
 // This code is only done in debug builds.
 #ifndef NDEBUG
 
-ThreadChecker::ThreadChecker() {
+ThreadChecker::ThreadChecker() : valid_thread_id_(kInvalidThreadId) {
   EnsureThreadIdAssigned();
 }
 
@@ -15,17 +15,20 @@ ThreadChecker::~ThreadChecker() {}
 
 bool ThreadChecker::CalledOnValidThread() const {
   EnsureThreadIdAssigned();
-  return *valid_thread_id_ == PlatformThread::CurrentId();
+  AutoLock auto_lock(lock_);
+  return valid_thread_id_ == PlatformThread::CurrentId();
 }
 
 void ThreadChecker::DetachFromThread() {
-  valid_thread_id_.reset();
+  AutoLock auto_lock(lock_);
+  valid_thread_id_ = kInvalidThreadId;
 }
 
 void ThreadChecker::EnsureThreadIdAssigned() const {
-  if (valid_thread_id_.get())
+  AutoLock auto_lock(lock_);
+  if (valid_thread_id_ != kInvalidThreadId)
     return;
-  valid_thread_id_.reset(new PlatformThreadId(PlatformThread::CurrentId()));
+  valid_thread_id_ = PlatformThread::CurrentId();
 }
 
 #endif  // NDEBUG
diff --git a/base/thread_checker.h b/base/thread_checker.h
index 5d5445e..c09bcbe 100644
--- a/base/thread_checker.h
+++ b/base/thread_checker.h
@@ -6,8 +6,10 @@
 #define BASE_THREAD_CHECKER_H_
 #pragma once
 
+#ifndef NDEBUG
+#include "base/lock.h"
 #include "base/platform_thread.h"
-#include "base/scoped_ptr.h"
+#endif // NDEBUG
 
 // Before using this class, please consider using NonThreadSafe as it
 // makes it much easier to determine the nature of your class.
@@ -47,8 +49,10 @@ class ThreadChecker {
  private:
   void EnsureThreadIdAssigned() const;
 
+  mutable Lock lock_;
   // This is mutable so that CalledOnValidThread can set it.
-  mutable scoped_ptr<PlatformThreadId> valid_thread_id_;
+  // It's guarded by |lock_|.
+  mutable PlatformThreadId valid_thread_id_;
 };
 #else
 // Do nothing in release mode.