Fix Resource Priorities and Scheduling (Blink Side)

Source/core/fetch/ResourceLoadPriorityOptimizer.cpp

Index: Source/core/fetch/ResourceLoadPriorityOptimizer.cpp
diff --git a/Source/core/fetch/ResourceLoadPriorityOptimizer.cpp b/Source/core/fetch/ResourceLoadPriorityOptimizer.cpp
index 721386ed1f684e72d47d52ed423ce3482c1c7656..047695ff7d5dada565a78e9c04722d8e689996e7 100644
--- a/Source/core/fetch/ResourceLoadPriorityOptimizer.cpp
+++ b/Source/core/fetch/ResourceLoadPriorityOptimizer.cpp
@@ -30,6 +30,7 @@
 
 #include "config.h"
 #include "core/fetch/ResourceLoadPriorityOptimizer.h"
+#include "core/frame/Settings.h"
 #include "core/layout/LayoutObject.h"
 #include "platform/TraceEvent.h"
 
@@ -55,6 +56,8 @@ ResourceLoadPriorityOptimizer::ResourceAndVisibility::~ResourceAndVisibility()
 }
 
 ResourceLoadPriorityOptimizer::ResourceLoadPriorityOptimizer()
+    : m_retrievedSettings(false)
+    , m_increaseFetchPriorities(false)
 {
 }
 
@@ -64,6 +67,15 @@ ResourceLoadPriorityOptimizer::~ResourceLoadPriorityOptimizer()
 
 void ResourceLoadPriorityOptimizer::addLayoutObject(LayoutObject* layoutObject)
 {
+    if (!m_retrievedSettings) {
+        // The list of image resources is populated by the layout objects in
+        // updateAllImageResourcePriorities so it is safe to only check the
+        // setting when the first layout object is added.  It is impossible to
+        // have images to update without having first populated at least one
+        // layout object.
+        m_increaseFetchPriorities = layoutObject->document().settings()->fetchIncreasePriorities();
+        m_retrievedSettings = true;
+    }
     m_objects.add(layoutObject);
     layoutObject->setHasPendingResourceUpdate(true);
 }
@@ -98,6 +110,11 @@ void ResourceLoadPriorityOptimizer::updateImageResourcesWithLoadPriority()
         ResourceLoadPriority priority = resource.value->status == Visible ?
             ResourceLoadPriorityLow : ResourceLoadPriorityVeryLow;
 
+        if (m_increaseFetchPriorities) {
+            priority = resource.value->status == Visible ?
+                ResourceLoadPriorityHigh : ResourceLoadPriorityLow;
+        }
+
         if (priority != resource.value->imageResource->resourceRequest().priority()) {
             resource.value->imageResource->mutableResourceRequest().setPriority(priority, resource.value->screenArea);
             resource.value->imageResource->didChangePriority(priority, resource.value->screenArea);