Raise the loading priority of in-viewport images.

Source/core/rendering/RenderImage.cpp

Index: Source/core/rendering/RenderImage.cpp
diff --git a/Source/core/rendering/RenderImage.cpp b/Source/core/rendering/RenderImage.cpp
index 478152baa4656289960a39095b7efb4f81ea8e30..d9ec71f548c13dc5f515c8937f4fad61137d1d98 100644
--- a/Source/core/rendering/RenderImage.cpp
+++ b/Source/core/rendering/RenderImage.cpp
@@ -31,6 +31,8 @@
 #include "HTMLNames.h"
 #include "core/editing/FrameSelection.h"
 #include "core/fetch/ImageResource.h"
+#include "core/fetch/ResourceLoadPriorityOptimizer.h"
+#include "core/fetch/ResourceLoader.h"
 #include "core/html/HTMLAreaElement.h"
 #include "core/html/HTMLImageElement.h"
 #include "core/html/HTMLInputElement.h"
@@ -573,6 +575,30 @@ void RenderImage::layout()
     updateInnerContentRect();
 }
 
+void RenderImage::didLayout(ResourceLoadPriorityOptimizer& optimizer)
+{
+    RenderReplaced::didLayout(optimizer);
+    updateImageLoadingPriority(optimizer);
+}
+
+void RenderImage::didScroll(ResourceLoadPriorityOptimizer& optimizer)
+{
+    RenderReplaced::didScroll(optimizer);
+    updateImageLoadingPriority(optimizer);
+}
+
+void RenderImage::updateImageLoadingPriority(ResourceLoadPriorityOptimizer& optimizer)
+{
+    if (m_imageResource->cachedImage() && !m_imageResource->cachedImage()->isLoaded()) {

[eseidel, 2013/11/27 20:58:35]

nit: Early returns are preferred over long if blocks.

[shatch, 2013/12/02 22:32:46]

Done. Also changed that in RenderBlock.

+        LayoutRect objectBounds = absoluteContentBox();
+        LayoutRect viewBounds = viewRect();
+
+        ResourceLoadPriorityOptimizer::VisibilityStatus status = viewBounds.intersects(objectBounds) ?
+            ResourceLoadPriorityOptimizer::Visible : ResourceLoadPriorityOptimizer::NotVisible;
+        optimizer.notifyImageResourceVisibility(m_imageResource->cachedImage(), status);
+    }
+}
+
 void RenderImage::computeIntrinsicRatioInformation(FloatSize& intrinsicSize, double& intrinsicRatio, bool& isPercentageIntrinsicSize) const
 {
     RenderReplaced::computeIntrinsicRatioInformation(intrinsicSize, intrinsicRatio, isPercentageIntrinsicSize);