Removing "using" declarations that import names in the C++ Standard library.

Source/core/editing/markup.cpp

Index: Source/core/editing/markup.cpp
diff --git a/Source/core/editing/markup.cpp b/Source/core/editing/markup.cpp
index 53b195c1762bcf667a4a872059bf23b31a3e4504..3fb5c4ea32ceeff27fd70edb833c869ed20ee4d6 100644
--- a/Source/core/editing/markup.cpp
+++ b/Source/core/editing/markup.cpp
@@ -60,8 +60,6 @@
 #include "wtf/StdLibExtras.h"
 #include "wtf/text/StringBuilder.h"
 
-using namespace std;
-
 namespace WebCore {
 
 using namespace HTMLNames;
@@ -120,8 +118,8 @@ static void completeURLs(DocumentFragment& fragment, const String& baseURL)
         }
     }
 
-    size_t numChanges = changes.size();
-    for (size_t i = 0; i < numChanges; ++i)
+    std::size_t numChanges = changes.size();
+    for (std::size_t i = 0; i < numChanges; ++i)
         changes[i].apply();
 }
 
@@ -213,7 +211,7 @@ String StyledMarkupAccumulator::takeResults()
     StringBuilder result;
     result.reserveCapacity(totalLength(m_reversedPrecedingMarkup) + length());
 
-    for (size_t i = m_reversedPrecedingMarkup.size(); i > 0; --i)
+    for (std::size_t i = m_reversedPrecedingMarkup.size(); i > 0; --i)
         result.append(m_reversedPrecedingMarkup[i - 1]);
 
     concatenateMarkup(result);
@@ -772,8 +770,8 @@ static void fillContainerFromString(ContainerNode* paragraph, const String& stri
     string.split('\t', true, tabList);
     StringBuilder tabText;
     bool first = true;
-    size_t numEntries = tabList.size();
-    for (size_t i = 0; i < numEntries; ++i) {
+    std::size_t numEntries = tabList.size();
+    for (std::size_t i = 0; i < numEntries; ++i) {
         const String& s = tabList[i];
 
         // append the non-tab textual part
@@ -871,8 +869,8 @@ PassRefPtrWillBeRawPtr<DocumentFragment> createFragmentFromText(Range* context,
 
     Vector<String> list;
     string.split('\n', true, list); // true gets us empty strings in the list
-    size_t numLines = list.size();
-    for (size_t i = 0; i < numLines; ++i) {
+    std::size_t numLines = list.size();
+    for (std::size_t i = 0; i < numLines; ++i) {
         const String& s = list[i];
 
         RefPtrWillBeRawPtr<Element> element = nullptr;