| Index: third_party/WebKit/Source/core/frame/FrameView.h
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| diff --git a/third_party/WebKit/Source/core/frame/FrameView.h b/third_party/WebKit/Source/core/frame/FrameView.h
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| index 709ec18135c0a371b54ab6f8dc772b498631a2ce..4f269d395187bb8bc935116e7dc1d53db481d923 100644
 | 
| --- a/third_party/WebKit/Source/core/frame/FrameView.h
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| +++ b/third_party/WebKit/Source/core/frame/FrameView.h
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| @@ -584,6 +584,9 @@
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|      // TODO(ojan): Merge this with IntersectionObserver once it lands.
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|      IntRect computeVisibleArea();
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|  
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| +    // Viewport size that should be used for viewport units (i.e. 'vh'/'vw').
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| +    FloatSize viewportSizeForViewportUnits() const;
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| +
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|  protected:
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|      // Scroll the content via the compositor.
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|      bool scrollContentsFastPath(const IntSize& scrollDelta);
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| 
 |