Adds some debugging code in hopes of tracking down a

crash. Specifically:

. Adds a CHECK to IDMap that evaluates to true if adding NULL. The
  default isn't to do this check.
. browser_shutdown CHECKs if the # RPHs changes while iterating
  through the RPHs.

BUG=15615
TEST=none

Review URL: http://codereview.chromium.org/150181

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@19779 0039d316-1c4b-4281-b951-d872f2087c98

base/id_map.h

@@ -28,12 +28,17 @@ class IDMap {
   // Note, use iterator->first to get the ID, iterator->second to get the T*
   typedef typename HashTable::const_iterator const_iterator;
 
-  IDMap() : next_id_(1) {
+  IDMap() : next_id_(1), check_on_null_data_(false) {
   }
-  IDMap(const IDMap& other) : next_id_(other.next_id_),
-                                        data_(other.data_) {
+  IDMap(const IDMap& other)
+      : next_id_(other.next_id_),
+        data_(other.data_),
+        check_on_null_data_(other.check_on_null_data_) {
   }
 
+  // Sets whether Add should CHECK if passed in NULL data. Default is false.
+  void set_check_on_null_data(bool value) { check_on_null_data_ = value; }
+
   const_iterator begin() const {
     return data_.begin();
   }
@@ -43,6 +48,7 @@ class IDMap {
 
   // Adds a view with an automatically generated unique ID. See AddWithID.
   int32 Add(T* data) {
+    CHECK(!check_on_null_data_ || data);
     int32 this_id = next_id_;
     DCHECK(data_.find(this_id) == data_.end()) << "Inserting duplicate item";
     data_[this_id] = data;
@@ -55,6 +61,7 @@ class IDMap {
   // this function, or allow this object to generate IDs and call Add. These
   // two methods may not be mixed, or duplicate IDs may be generated
   void AddWithID(T* data, int32 id) {
+    CHECK(!check_on_null_data_ || data);
     DCHECK(data_.find(id) == data_.end()) << "Inserting duplicate item";
     data_[id] = data;
   }
@@ -88,6 +95,10 @@ class IDMap {
   int32 next_id_;
 
   HashTable data_;
+
+ private:
+  // See description above setter.
+  bool check_on_null_data_;
 };
 
 #endif  // BASE_ID_MAP_H__

chrome/browser/browser_shutdown.cc

@@ -65,6 +65,7 @@ void OnShutdownStarting(ShutdownType type) {
     // a no-op in some cases, so we still need to go through the normal
     // shutdown path for the ones that didn't exit here.
     shutdown_num_processes_slow_ = 0;
+    size_t start_rph_size = RenderProcessHost::size();
     for (RenderProcessHost::iterator hosts = RenderProcessHost::begin();
          hosts != RenderProcessHost::end();
          ++hosts) {
@@ -74,6 +75,9 @@ void OnShutdownStarting(ShutdownType type) {
         // higher up, it's not possible to get here. Confirm this and change
         // FastShutdownIfPossible to just be FastShutdown.
         shutdown_num_processes_slow_++;
+      // The number of RPHs should not have changed as the result of invoking
+      // FastShutdownIfPossible.
+      CHECK(start_rph_size == RenderProcessHost::size());
     }
   }
 }

chrome/browser/renderer_host/render_process_host.cc

@@ -85,6 +85,7 @@ RenderProcessHost::RenderProcessHost(Profile* profile)
       pid_(-1),
       profile_(profile),
       sudden_termination_allowed_(true) {
+  all_hosts.set_check_on_null_data(true);
 }
 
 RenderProcessHost::~RenderProcessHost() {