Only track http and https in duplicate resource handler metrics

content/browser/renderer_host/duplicate_content_resource_handler.cc

Index: content/browser/renderer_host/duplicate_content_resource_handler.cc
diff --git a/content/browser/renderer_host/duplicate_content_resource_handler.cc b/content/browser/renderer_host/duplicate_content_resource_handler.cc
index 5760db45bf90a2af5eeabcf2290a1d6c22ef1b8a..c94f511594bf945f977b8eba0b7c0b9042d72074 100644
--- a/content/browser/renderer_host/duplicate_content_resource_handler.cc
+++ b/content/browser/renderer_host/duplicate_content_resource_handler.cc
@@ -51,6 +51,11 @@ DuplicateContentResourceHandler::DuplicateContentResourceHandler(
       request_(request),
       pmurhash_ph1_(0),
       pmurhash_pcarry_(0) {
+  // Ignore everything that's not http/https. Specifically, exclude data and
+  // blob URLs which can be generated by content and cause the maintained sets
+  // to grow without bounds.
+  const GURL& url = request_->url();
+  track_request_ = url.SchemeIs("http") || url.SchemeIs("https");
 }
 
 DuplicateContentResourceHandler::~DuplicateContentResourceHandler() {
@@ -71,9 +76,11 @@ bool DuplicateContentResourceHandler::OnWillRead(int request_id,
 bool DuplicateContentResourceHandler::OnReadCompleted(int request_id,
                                                       int bytes_read,
                                                       bool* defer) {
-  PMurHash32_Process(&pmurhash_ph1_, &pmurhash_pcarry_,
-                      read_buffer_->data(), bytes_read);
-  bytes_read_ += bytes_read;
+  if (track_request_) {
+    PMurHash32_Process(&pmurhash_ph1_, &pmurhash_pcarry_,
+                       read_buffer_->data(), bytes_read);
+    bytes_read_ += bytes_read;
+  }
   return next_handler_->OnReadCompleted(request_id, bytes_read, defer);
 }
 
@@ -81,9 +88,10 @@ bool DuplicateContentResourceHandler::OnResponseCompleted(
     int request_id,
     const net::URLRequestStatus& status,
     const std::string& security_info) {
-
-  if (status.is_success())
-    RecordContentMetrics();
+  if (track_request_) {
+    if (status.is_success())
+      RecordContentMetrics();
+  }
 
   return next_handler_->OnResponseCompleted(request_id, status, security_info);
 }
@@ -98,12 +106,11 @@ void DuplicateContentResourceHandler::RecordContentMetrics() {
 
   // Combine the contents_hash with the url, so we can test if future content
   // identical resources have the same original url or not.
-  MH_UINT32 hashed_with_url;
   const std::string& url_spec = request_->url().spec();
   PMurHash32_Process(&pmurhash_ph1_, &pmurhash_pcarry_,
                      url_spec.data(), url_spec.length());
-  hashed_with_url = PMurHash32_Result(pmurhash_ph1_, pmurhash_pcarry_,
-                                      url_spec.length() + bytes_read_);
+  MH_UINT32 hashed_with_url = PMurHash32_Result(
+      pmurhash_ph1_, pmurhash_pcarry_, url_spec.length() + bytes_read_);
 
   DVLOG(4) << "url: " << url_spec;
   DVLOG(4) << "contents hash: " << contents_hash;