Count presence of viewport tag as mobile-friendly

third_party/WebKit/Source/core/frame/VisualViewport.cpp

Index: third_party/WebKit/Source/core/frame/VisualViewport.cpp
diff --git a/third_party/WebKit/Source/core/frame/VisualViewport.cpp b/third_party/WebKit/Source/core/frame/VisualViewport.cpp
index 61572c8f2ff53a1aec04dea03dc4032b8cd09927..31738482ef96e1e29ef314dcef334a24af410f0f 100644
--- a/third_party/WebKit/Source/core/frame/VisualViewport.cpp
+++ b/third_party/WebKit/Source/core/frame/VisualViewport.cpp
@@ -776,13 +776,13 @@ bool VisualViewport::shouldDisableDesktopWorkarounds() const {
     return false;
 
   // A document is considered adapted to small screen UAs if one of these holds:
-  // 1. The author specified viewport has a constrained width that is equal to
-  //    the initial viewport width.
+  // 1. The author specified viewport has a constrained width that is smaller or
+  //    equal to the initial viewport width.
   // 2. The author has disabled viewport zoom.
   const PageScaleConstraints& constraints =
       frameHost().pageScaleConstraintsSet().pageDefinedConstraints();
 
-  return mainFrame()->view()->layoutSize().width() == m_size.width() ||
+  return mainFrame()->view()->layoutSize().width() <= m_size.width() ||

[aelias_OOO_until_Jul13, 2016/10/24 21:48:59]

Hmm, I think we should decouple this from the details of resolved viewport width
and screen size entirely.

Could you delete this logic entirely and merge this detection with
matchesHeuristicsForGpuRasterization?  That checks if the
ViewportDescription.isSpecifiedByAuthor.  Might make sense to rename some of the
GPU-raster-related names to m_viewportSpecifiedByAuthor as well and generalize
it to this use.

(The other uses of shouldDisableDesktopWorkarounds are for tap disambiguation
stuff and double-tap zoom stuff, both of which should also be OK with switching
to *any* viewport tag.)

[wychen, 2016/10/24 23:18:52]

Done.

          (constraints.minimumScale == constraints.maximumScale &&
           constraints.minimumScale != -1);
 }