Bug 890195 - device-width media queries should use the page width, not the actual device width. r=bz

docshell/base/nsDocShell.cpp

@@ -755,6 +755,7 @@ nsDocShell::nsDocShell():
     mIsAppTab(false),
     mUseGlobalHistory(false),
     mInPrivateBrowsing(false),
+    mDeviceSizeIsPageSize(false),
     mFiredUnloadEvent(false),
     mEODForCurrentDocument(false),
     mURIResultedInDocument(false),
@@ -3920,6 +3921,27 @@ nsDocShell::GetCurrentSHEntry(nsISHEntry** aEntry, bool* aOSHE)
     return NS_OK;
 }
 
+NS_IMETHODIMP
+nsDocShell::SetDeviceSizeIsPageSize(bool aValue)
+{
+    if (mDeviceSizeIsPageSize != aValue) {
+      mDeviceSizeIsPageSize = aValue;
+      nsRefPtr<nsPresContext> presContext;
+      GetPresContext(getter_AddRefs(presContext));
+      if (presContext) {
+          presContext->MediaFeatureValuesChanged(presContext->eAlwaysRebuildStyle);
+      }
+    }
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocShell::GetDeviceSizeIsPageSize(bool* aValue)
+{
+    *aValue = mDeviceSizeIsPageSize;
+    return NS_OK;
+}
+
 void
 nsDocShell::ClearFrameHistory(nsISHEntry* aEntry)
 {