Prevent duplicate content script injection defined in manifest.json (reland)

extensions/renderer/programmatic_script_injector.cc

Index: extensions/renderer/programmatic_script_injector.cc
diff --git a/extensions/renderer/programmatic_script_injector.cc b/extensions/renderer/programmatic_script_injector.cc
index e52885eee742fe261107ff1040b6628d9e532a83..f4af8d7f25529a6f18df5710fdfa06ce9fc01432 100644
--- a/extensions/renderer/programmatic_script_injector.cc
+++ b/extensions/renderer/programmatic_script_injector.cc
@@ -18,6 +18,7 @@
 #include "extensions/renderer/injection_host.h"
 #include "extensions/renderer/renderer_extension_registry.h"
 #include "extensions/renderer/script_context.h"
+#include "extensions/renderer/scripts_run_info.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 #include "third_party/WebKit/public/web/WebDocument.h"
 #include "third_party/WebKit/public/web/WebLocalFrame.h"
@@ -59,13 +60,17 @@ bool ProgrammaticScriptInjector::ExpectsResults() const {
 }
 
 bool ProgrammaticScriptInjector::ShouldInjectJs(
-    UserScript::RunLocation run_location) const {
-  return GetRunLocation() == run_location && params_->is_javascript;
+    UserScript::RunLocation run_location,
+    ScriptsRunInfo* scripts_run_info) const {
+  return GetRunLocation() == run_location && params_->is_javascript &&
+         !scripts_run_info->injected_scripts.empty();

[Devlin, 2016/08/03 23:34:44]

This line means that we only inject js if there's already been a js injection,
doesn't it?

 }
 
 bool ProgrammaticScriptInjector::ShouldInjectCss(
-    UserScript::RunLocation run_location) const {
-  return GetRunLocation() == run_location && !params_->is_javascript;
+    UserScript::RunLocation run_location,
+    ScriptsRunInfo* scripts_run_info) const {
+  return GetRunLocation() == run_location && !params_->is_javascript &&
+         !scripts_run_info->injected_scripts.empty();
 }
 
 PermissionsData::AccessType ProgrammaticScriptInjector::CanExecuteOnFrame(
@@ -94,7 +99,8 @@ PermissionsData::AccessType ProgrammaticScriptInjector::CanExecuteOnFrame(
 }
 
 std::vector<blink::WebScriptSource> ProgrammaticScriptInjector::GetJsSources(
-    UserScript::RunLocation run_location) const {
+    UserScript::RunLocation run_location,
+    ScriptsRunInfo* scripts_run_info) const {
   DCHECK_EQ(GetRunLocation(), run_location);
   DCHECK(params_->is_javascript);
 
@@ -105,7 +111,8 @@ std::vector<blink::WebScriptSource> ProgrammaticScriptInjector::GetJsSources(
 }
 
 std::vector<std::string> ProgrammaticScriptInjector::GetCssSources(
-    UserScript::RunLocation run_location) const {
+    UserScript::RunLocation run_location,
+    ScriptsRunInfo* scripts_run_info) const {
   DCHECK_EQ(GetRunLocation(), run_location);
   DCHECK(!params_->is_javascript);