Avoid a string copy in URLRequestResourceBundleJob::GetData().

chrome/browser/extensions/chrome_url_request_util.cc

Index: chrome/browser/extensions/chrome_url_request_util.cc
diff --git a/chrome/browser/extensions/chrome_url_request_util.cc b/chrome/browser/extensions/chrome_url_request_util.cc
index c89350aa3d05dbd19cc41baa9980db278d61b5b7..b37860f2e39e84c1cb9e64da133ae1de979f5887 100644
--- a/chrome/browser/extensions/chrome_url_request_util.cc
+++ b/chrome/browser/extensions/chrome_url_request_util.cc
@@ -59,10 +59,11 @@ class URLRequestResourceBundleJob : public net::URLRequestSimpleJob {
   }
 
   // Overridden from URLRequestSimpleJob:
-  int GetData(std::string* mime_type,
-              std::string* charset,
-              std::string* data,
-              const net::CompletionCallback& callback) const override {
+  int GetRefCountedData(
+      std::string* mime_type,
+      std::string* charset,
+      scoped_refptr<base::RefCountedMemory>* data,
+      const net::CompletionCallback& callback) const override {
     // TODO(vadimt): Remove ScopedTracker below once crbug.com/422489 is fixed.
     tracked_objects::ScopedTracker tracking_profile(
         FROM_HERE_WITH_EXPLICIT_FUNCTION(
@@ -83,7 +84,8 @@ class URLRequestResourceBundleJob : public net::URLRequestSimpleJob {
         FROM_HERE_WITH_EXPLICIT_FUNCTION(
             "422489 URLRequestResourceBundleJob::GetData 1.5"));
 
-    *data = resource_as_string_piece.as_string();
+    *data = new base::RefCountedStaticMemory(resource_as_string_piece.data(),
+                                             resource_as_string_piece.size());
 
     // TODO(vadimt): Remove ScopedTracker below once crbug.com/422489 is fixed.
     tracked_objects::ScopedTracker tracking_profile2(
@@ -91,10 +93,9 @@ class URLRequestResourceBundleJob : public net::URLRequestSimpleJob {
             "422489 URLRequestResourceBundleJob::GetData 2"));
 
     // Add the Content-Length header now that we know the resource length.
-    response_info_.headers->AddHeader(
-        base::StringPrintf("%s: %s",
-                           net::HttpRequestHeaders::kContentLength,
-                           base::UintToString(data->size()).c_str()));
+    response_info_.headers->AddHeader(base::StringPrintf(
+        "%s: %s", net::HttpRequestHeaders::kContentLength,
+        base::UintToString(resource_as_string_piece.size()).c_str()));
 
     // TODO(vadimt): Remove ScopedTracker below once crbug.com/422489 is fixed.
     tracked_objects::ScopedTracker tracking_profile3(
@@ -103,17 +104,12 @@ class URLRequestResourceBundleJob : public net::URLRequestSimpleJob {
 
     std::string* read_mime_type = new std::string;
     bool posted = base::PostTaskAndReplyWithResult(
-        BrowserThread::GetBlockingPool(),
-        FROM_HERE,
-        base::Bind(&net::GetMimeTypeFromFile,
-                   filename_,
+        BrowserThread::GetBlockingPool(), FROM_HERE,
+        base::Bind(&net::GetMimeTypeFromFile, filename_,
                    base::Unretained(read_mime_type)),
         base::Bind(&URLRequestResourceBundleJob::OnMimeTypeRead,
-                   weak_factory_.GetWeakPtr(),
-                   mime_type,
-                   charset,
-                   data,
-                   base::Owned(read_mime_type),
+                   weak_factory_.GetWeakPtr(), mime_type, charset,
+                   resource_as_string_piece, base::Owned(read_mime_type),
                    callback));
     DCHECK(posted);
 
@@ -129,7 +125,7 @@ class URLRequestResourceBundleJob : public net::URLRequestSimpleJob {
 
   void OnMimeTypeRead(std::string* out_mime_type,
                       std::string* charset,
-                      std::string* data,
+                      base::StringPiece data,
                       std::string* read_mime_type,
                       const net::CompletionCallback& callback,
                       bool read_result) {
@@ -137,7 +133,7 @@ class URLRequestResourceBundleJob : public net::URLRequestSimpleJob {
     if (StartsWithASCII(*read_mime_type, "text/", false)) {
       // All of our HTML files should be UTF-8 and for other resource types
       // (like images), charset doesn't matter.
-      DCHECK(base::IsStringUTF8(*data));
+      DCHECK(base::IsStringUTF8(data));
       *charset = "utf-8";
     }
     int result = read_result ? net::OK : net::ERR_INVALID_URL;