fix about:memory and memory histograms to show extensions more clearly

chrome/common/child_process_info.cc

Index: chrome/common/child_process_info.cc
diff --git a/chrome/common/child_process_info.cc b/chrome/common/child_process_info.cc
index 87745787fa50f2047cfc4296ba055dcd3fe4f13f..fd2e9fd7f33b3050a8c05fd594d4ded20d71499f 100644
--- a/chrome/common/child_process_info.cc
+++ b/chrome/common/child_process_info.cc
@@ -18,6 +18,7 @@
 
 ChildProcessInfo::ChildProcessInfo(const ChildProcessInfo& original)
     : type_(original.type_),
+      renderer_type_(original.renderer_type_),
       name_(original.name_),
       version_(original.version_),
       id_(original.id_),
@@ -31,6 +32,7 @@ ChildProcessInfo& ChildProcessInfo::operator=(
     const ChildProcessInfo& original) {
   if (&original != this) {
     type_ = original.type_;
+    renderer_type_ = original.renderer_type_;
     name_ = original.name_;
     version_ = original.version_;
     id_ = original.id_;
@@ -39,6 +41,7 @@ ChildProcessInfo& ChildProcessInfo::operator=(
   return *this;
 }
 
+// static
 std::string ChildProcessInfo::GetTypeNameInEnglish(
     ChildProcessInfo::ProcessType type) {
   switch (type) {
@@ -73,6 +76,33 @@ std::string ChildProcessInfo::GetTypeNameInEnglish(
   }
 }
 
+// static
+std::string ChildProcessInfo::GetRendererTypeNameInEnglish(
+    ChildProcessInfo::RendererProcessType type) {
+  switch (type) {
+    case RENDERER_NORMAL:
+      return "Tab";
+    case RENDERER_CHROME:
+      return "Tab (Chrome)";
+    case RENDERER_EXTENSION:
+      return "Extension";
+    case RENDERER_UNKNOWN:
+    default:
+      NOTREACHED() << "Unknown renderer process type!";
+      return "Unknown";
+  }
+}
+
+// static
+std::string ChildProcessInfo::GetFullTypeNameInEnglish(
+    ChildProcessInfo::ProcessType type,
+    ChildProcessInfo::RendererProcessType rtype) {
+  if (type == RENDER_PROCESS)
+    return GetRendererTypeNameInEnglish(rtype);
+  return GetTypeNameInEnglish(type);
+}
+
+
 string16 ChildProcessInfo::GetLocalizedTitle() const {
   string16 title = WideToUTF16Hack(name_);
   if (type_ == ChildProcessInfo::PLUGIN_PROCESS && title.empty())
@@ -125,6 +155,7 @@ string16 ChildProcessInfo::GetLocalizedTitle() const {
 }
 
 ChildProcessInfo::ChildProcessInfo(ProcessType type, int id) : type_(type) {
+  renderer_type_ = RENDERER_UNKNOWN;
   if (id == -1)
     id_ = GenerateChildProcessUniqueId();
   else