[WIP] ImageResourceClient->ImageResourceObserver

third_party/WebKit/Source/core/fetch/ImageResource.cpp

Index: third_party/WebKit/Source/core/fetch/ImageResource.cpp
diff --git a/third_party/WebKit/Source/core/fetch/ImageResource.cpp b/third_party/WebKit/Source/core/fetch/ImageResource.cpp
index a252a4e72b0c94a5dae54dee86182b0b529d753e..f9e180809eacaf8f92c6a265d1738e6ff1b1c21c 100644
--- a/third_party/WebKit/Source/core/fetch/ImageResource.cpp
+++ b/third_party/WebKit/Source/core/fetch/ImageResource.cpp
@@ -23,10 +23,9 @@
 
 #include "core/fetch/ImageResource.h"
 
-#include "core/fetch/ImageResourceClient.h"
+#include "core/fetch/ImageResourceObserver.h"
 #include "core/fetch/MemoryCache.h"
 #include "core/fetch/ResourceClient.h"
-#include "core/fetch/ResourceClientWalker.h"
 #include "core/fetch/ResourceFetcher.h"
 #include "core/fetch/ResourceLoader.h"
 #include "core/svg/graphics/SVGImage.h"
@@ -111,26 +110,36 @@ void ImageResource::load(ResourceFetcher* fetcher, const ResourceLoaderOptions&
         setLoading(false);
 }
 
-void ImageResource::didAddClient(ResourceClient* c)
+void ImageResource::addObserver(ImageResourceObserver* observer)
 {
     if (m_data && !m_image && !errorOccurred()) {
         createImage();
         m_image->setData(m_data, true);
     }
 
-    ASSERT(c->resourceClientType() == ImageResourceClient::expectedType());
     if (m_image && !m_image->isNull())
-        static_cast<ImageResourceClient*>(c)->imageChanged(this);
-
-    Resource::didAddClient(c);
+        observer->imageChanged(this);
+    m_observers.add(observer);
 }
 
-void ImageResource::didRemoveClient(ResourceClient* c)
+void ImageResource::removeObserver(ImageResourceObserver* observer)
 {
-    ASSERT(c);
-    ASSERT(c->resourceClientType() == ImageResourceClient::expectedType());
+    ASSERT(observer);
+    ASSERT(m_observers.contains(observer));
+    m_observers.remove(observer);
+}
 
-    Resource::didRemoveClient(c);
+ResourcePriority ImageResource::priorityFromClients()
+{
+    ResourcePriority priority;
+    for (const auto& observer : m_observers) {
+        ResourcePriority nextPriority = observer.key->computeResourcePriority();
+        if (nextPriority.visibility == ResourcePriority::NotVisible)
+            continue;
+        priority.visibility = ResourcePriority::Visible;
+        priority.intraPriorityValue += nextPriority.intraPriorityValue;
+    }
+    return priority;
 }
 
 bool ImageResource::isSafeToUnlock() const
@@ -247,13 +256,12 @@ void ImageResource::computeIntrinsicDimensions(Length& intrinsicWidth, Length& i
 
 void ImageResource::notifyObservers(const IntRect* changeRect)
 {
-    ResourceClientWalker<ImageResourceClient> w(m_clients);
-    while (ImageResourceClient* c = w.next())
-        c->imageChanged(this, changeRect);
-
-    ResourceClientWalker<ImageResourceClient> w2(m_finishedClients);
-    while (ImageResourceClient* c = w2.next())
-        c->imageChanged(this, changeRect);
+    WillBeHeapVector<ImageResourceObserver*> observers(m_observers.size());
+    size_t index = 0;
+    for (const auto& observer : m_observers)
+        observers[index++] = observer.key;
+    for (auto observer : observers)
+        observer->imageChanged(this, changeRect);
 }
 
 void ImageResource::clear()
@@ -391,18 +399,10 @@ bool ImageResource::shouldPauseAnimation(const blink::Image* image)
     if (!image || image != m_image)
         return false;
 
-    ResourceClientWalker<ImageResourceClient> w(m_clients);
-    while (ImageResourceClient* c = w.next()) {
-        if (c->willRenderImage(this))
-            return false;
-    }
-
-    ResourceClientWalker<ImageResourceClient> w2(m_finishedClients);
-    while (ImageResourceClient* c = w2.next()) {
-        if (c->willRenderImage(this))
+    for (const auto& observer : m_observers) {
+        if (observer.key->willRenderImage())
             return false;
     }
-
     return true;
 }
 
@@ -419,15 +419,8 @@ void ImageResource::updateImageAnimationPolicy()
         return;
 
     ImageAnimationPolicy newPolicy = ImageAnimationPolicyAllowed;
-    ResourceClientWalker<ImageResourceClient> w(m_clients);
-    while (ImageResourceClient* c = w.next()) {
-        if (c->getImageAnimationPolicy(this, newPolicy))
-            break;
-    }
-
-    ResourceClientWalker<ImageResourceClient> w2(m_finishedClients);
-    while (ImageResourceClient* c = w2.next()) {
-        if (c->getImageAnimationPolicy(this, newPolicy))
+    for (const auto& observer : m_observers) {
+        if (observer.key->getImageAnimationPolicy(newPolicy))
             break;
     }