Adds DevTools commands for forced viewport override.

third_party/WebKit/Source/web/WebViewImpl.cpp

Index: third_party/WebKit/Source/web/WebViewImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebViewImpl.cpp b/third_party/WebKit/Source/web/WebViewImpl.cpp
index 9bc4335ce6d61d0e6cfa6575c8a292b7bff37569..5caafc3efc71ac86da0287102f0ed5e4c94a17e2 100644
--- a/third_party/WebKit/Source/web/WebViewImpl.cpp
+++ b/third_party/WebKit/Source/web/WebViewImpl.cpp
@@ -110,6 +110,7 @@
 #include "platform/UserGestureIndicator.h"
 #include "platform/exported/WebActiveGestureAnimation.h"
 #include "platform/fonts/FontCache.h"
+#include "platform/geometry/FloatRect.h"
 #include "platform/graphics/Color.h"
 #include "platform/graphics/CompositorMutatorClient.h"
 #include "platform/graphics/FirstPaintInvalidationTracking.h"
@@ -420,7 +421,6 @@ WebViewImpl::WebViewImpl(WebViewClient* client, WebPageVisibilityState visibilit
     , m_doingDragAndDrop(false)
     , m_ignoreInputEvents(false)
     , m_compositorDeviceScaleFactorOverride(0)
-    , m_rootLayerScale(1)
     , m_suppressNextKeypressEvent(false)
     , m_imeAcceptEvents(true)
     , m_operationsAllowed(WebDragOperationNone)
@@ -3844,17 +3844,19 @@ void WebViewImpl::setCompositorDeviceScaleFactorOverride(float deviceScaleFactor
         updateLayerTreeDeviceScaleFactor();
 }
 
-void WebViewImpl::setRootLayerTransform(const WebSize& rootLayerOffset, float rootLayerScale)
+void WebViewImpl::setRootLayerTransform(const TransformationMatrix& transform)
 {
-    if (m_rootLayerScale == rootLayerScale && m_rootLayerOffset == rootLayerOffset)
+    if (transform == m_rootLayerTransform)
         return;
-    m_rootLayerScale = rootLayerScale;
-    m_rootLayerOffset = rootLayerOffset;
-    if (mainFrameImpl())
-        mainFrameImpl()->setInputEventsTransformForEmulation(m_rootLayerOffset, m_rootLayerScale);
+    m_rootLayerTransform = transform;
     updateRootLayerTransform();
 }
 
+TransformationMatrix WebViewImpl::getRootLayerTransformForTesting() const
+{
+    return m_rootLayerTransform;
+}
+
 void WebViewImpl::enableDeviceEmulation(const WebDeviceEmulationParams& params)
 {
     m_devToolsEmulator->enableDeviceEmulation(params);
@@ -4090,6 +4092,12 @@ void WebViewImpl::pageScaleFactorChanged()
     pageScaleConstraintsSet().setNeedsReset(false);
     updateLayerTreeViewport();
     m_client->pageScaleFactorChanged();
+    m_devToolsEmulator->mainFrameScrollOrScaleChanged();

[chrishtr, 2016/08/22 22:00:42]

This seems new. Why was it not needed before?

[Eric Seckler, 2016/08/23 09:32:19]

Should have been there in the previous version of the patch you looked at, too.
It's needed to notify the emulator about a page scale change, so that it can
update the viewport transform (to ensure the |scale| param of forceViewport is
enforced relative to a page scale of 1.0).

+}
+
+void WebViewImpl::mainFrameScrollOffsetChanged()
+{
+    m_devToolsEmulator->mainFrameScrollOrScaleChanged();
 }
 
 bool WebViewImpl::useExternalPopupMenus()
@@ -4420,12 +4428,8 @@ void WebViewImpl::updateLayerTreeDeviceScaleFactor()
 
 void WebViewImpl::updateRootLayerTransform()
 {
-    if (m_visualViewportContainerLayer) {
-        TransformationMatrix transform;
-        transform.translate(m_rootLayerOffset.width, m_rootLayerOffset.height);
-        transform = transform.scale(m_rootLayerScale);
-        m_visualViewportContainerLayer->setTransform(transform);
-    }
+    if (m_visualViewportContainerLayer)
+        m_visualViewportContainerLayer->setTransform(m_rootLayerTransform);
 }
 
 bool WebViewImpl::detectContentOnTouch(const GestureEventWithHitTestResults& targetedEvent)