Adds DevTools commands for forced viewport override.

third_party/WebKit/Source/core/frame/FrameView.h

Index: third_party/WebKit/Source/core/frame/FrameView.h
diff --git a/third_party/WebKit/Source/core/frame/FrameView.h b/third_party/WebKit/Source/core/frame/FrameView.h
index 7cf81e9a6ff81b8a5ea70ba08710466ae6e12505..f2ae497fef3cf4469e5aec2e37d9cf7b353cfc8e 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.h
+++ b/third_party/WebKit/Source/core/frame/FrameView.h
@@ -448,6 +448,14 @@ public:
     IntRect visibleContentRect(IncludeScrollbarsInRect = ExcludeScrollbars) const override;
     IntSize visibleContentSize(IncludeScrollbarsInRect = ExcludeScrollbars) const;
 
+    // Set a custom recording area. Used for composited area overrides to ensure

[Sami, 2016/08/11 10:09:07]

I still think we should call this painting instead of recording, because cc's
recording step basically just means telling Blink to paint things.

[Eric Seckler, 2016/08/11 11:34:45]

Alright :)

+    // that the content inside the area is recorded. If not set, the recording
+    // area defaults to visibleContentRect().
+    void setVisibleContentRectForRecording(const IntRect&);
+    void resetVisibleContentRectForRecording();
+    IntRect visibleContentRectForRecording() const;
+    IntSize visibleContentSizeForRecording() const;

[Sami, 2016/08/11 10:09:07]

Unused?

[Eric Seckler, 2016/08/11 11:34:45]

True, don't need it ATM.

+
     // Functions for getting/setting the size of the document contained inside the FrameView (as an IntSize or as individual width and height
     // values).
     IntSize contentsSize() const override; // Always at least as big as the visibleWidth()/visibleHeight().
@@ -874,6 +882,7 @@ private:
     DoubleSize m_pendingScrollDelta;
     DoublePoint m_scrollPosition;
     IntSize m_contentsSize;
+    std::unique_ptr<IntRect> m_visibleContentRectForRecording;
 
     int m_scrollbarsAvoidingResizer;
     bool m_scrollbarsSuppressed;