Implement desktop compatibility viewport

cc/layer_tree_host.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/layer_tree_host.h"
 
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/message_loop.h"
 #include "base/stl_util.h"
@@ skipping 293 matching lines @@
         // considered active.
         syncTree->DidBecomeActive();
     }
 
     hostImpl->setViewportSize(layoutViewportSize(), deviceViewportSize());
     hostImpl->setDeviceScaleFactor(deviceScaleFactor());
     hostImpl->setPageScaleFactorAndLimits(m_pageScaleFactor, m_minPageScaleFactor, m_maxPageScaleFactor);
     hostImpl->setDebugState(m_debugState);
     hostImpl->savePaintTime(m_renderingStats.totalPaintTime);
 
+    if (LayerImpl* rootScrollLayer = syncTree->RootScrollLayer()) {
+        fprintf (stderr, "debug: %d %d\n", rootScrollLayer->sentDesktopCompatibilityViewportOffsetFromScrollPositionDelta().x(), rootScrollLayer->sentDesktopCompatibilityViewportOffsetFromScrollPositionDelta().y());
+        // FIXME FIXME FIXME
+        rootScrollLayer->setDesktopCompatibilityViewportOffsetFromScrollPosition(rootScrollLayer->desktopCompatibilityViewportOffsetFromScrollPosition() + rootScrollLayer->sentDesktopCompatibilityViewportOffsetFromScrollPositionDelta());
+        rootScrollLayer->setDesktopCompatibilityViewportOffsetFromScrollPositionDelta(rootScrollLayer->desktopCompatibilityViewportOffsetFromScrollPositionDelta() - rootScrollLayer->sentDesktopCompatibilityViewportOffsetFromScrollPositionDelta());
+        rootScrollLayer->setSentDesktopCompatibilityViewportOffsetFromScrollPositionDelta(gfx::Vector2d());
+    }
+
     if (newImplTreeHasNoEvictedResources) {
         if (syncTree->ContentsTexturesPurged())
             syncTree->ResetContentsTexturesPurged();
     }
 
     m_commitNumber++;
 }
 
 void LayerTreeHost::willCommit()
 {
@@ skipping 417 matching lines @@
 
     for (size_t i = 0; i < info.scrolls.size(); ++i) {
         Layer* layer = LayerTreeHostCommon::findLayerInSubtree(m_rootLayer.get(), info.scrolls[i].layerId);
         if (!layer)
             continue;
         if (layer == rootScrollLayer)
             rootScrollDelta += info.scrolls[i].scrollDelta;
         else
             layer->setScrollOffset(layer->scrollOffset() + info.scrolls[i].scrollDelta);
     }
-    if (!rootScrollDelta.IsZero() || info.pageScaleDelta != 1)
-        m_client->applyScrollAndScale(rootScrollDelta, info.pageScaleDelta);
+    if (!rootScrollDelta.IsZero() || info.pageScaleDelta != 1 || !info.desktopCompatibilityViewportOffsetFromScrollPositionDelta.IsZero())
+        m_client->applyScrollAndScale(rootScrollDelta, info.pageScaleDelta, info.desktopCompatibilityViewportOffsetFromScrollPositionDelta);
 }
 
 void LayerTreeHost::setImplTransform(const gfx::Transform& transform)
 {
     m_implTransform = transform;
 }
 
 void LayerTreeHost::startRateLimiter(WebKit::WebGraphicsContext3D* context)
 {
     if (m_animating)
@@ skipping 87 matching lines @@
     for (size_t childIndex = 0; childIndex < layer->children().size(); ++childIndex)
         setAnimationEventsRecursive(events, layer->children()[childIndex].get(), wallClockTime);
 }
 
 skia::RefPtr<SkPicture> LayerTreeHost::capturePicture()
 {
     return m_proxy->capturePicture();
 }
 
 }  // namespace cc