Use base namespace for string16 in chrome/renderer.

chrome/renderer/spellchecker/spellcheck.h

Index: chrome/renderer/spellchecker/spellcheck.h
diff --git a/chrome/renderer/spellchecker/spellcheck.h b/chrome/renderer/spellchecker/spellcheck.h
index 0ba206ac6b0934a64a95e87eaa9644a5166e061f..bfc6e7188b9d4451a2d810c449d4c01afded88c4 100644
--- a/chrome/renderer/spellchecker/spellcheck.h
+++ b/chrome/renderer/spellchecker/spellcheck.h
@@ -71,13 +71,13 @@ class SpellCheck : public content::RenderProcessObserver,
                       int tag,
                       int* misspelling_start,
                       int* misspelling_len,
-                      std::vector<string16>* optional_suggestions);
+                      std::vector<base::string16>* optional_suggestions);
 
   // SpellCheck a paragraph.
   // Returns true if |text| is correctly spelled, false otherwise.
   // If the spellchecker failed to initialize, always returns true.
   bool SpellCheckParagraph(
-      const string16& text,
+      const base::string16& text,
       blink::WebVector<blink::WebTextCheckingResult>* results);
 
   // Find a possible correctly spelled word for a misspelled word. Computes an
@@ -86,12 +86,12 @@ class SpellCheck : public content::RenderProcessObserver,
   // NOTE: If using the platform spellchecker, this will send a *lot* of sync
   // IPCs. We should probably refactor this if we ever plan to take it out from
   // behind its command line flag.
-  string16 GetAutoCorrectionWord(const string16& word, int tag);
+  base::string16 GetAutoCorrectionWord(const base::string16& word, int tag);
 
   // Requests to spellcheck the specified text in the background. This function
   // posts a background task and calls SpellCheckParagraph() in the task.
 #if !defined (OS_MACOSX)
-  void RequestTextChecking(const string16& text,
+  void RequestTextChecking(const base::string16& text,
                            blink::WebTextCheckingCompletion* completion);
 #endif
 
@@ -102,7 +102,7 @@ class SpellCheck : public content::RenderProcessObserver,
   void CreateTextCheckingResults(
       ResultFilter filter,
       int line_offset,
-      const string16& line_text,
+      const base::string16& line_text,
       const std::vector<SpellCheckResult>& spellcheck_results,
       blink::WebVector<blink::WebTextCheckingResult>* textcheck_results);