Add a font inflation data structure per block formatting context. (Bug 706193, patch 2) r=roc

This structure is per block formatting context because we have to make a
single inflation decision for things like consecutive runs of paragraphs
of text.  Inflating some paragraphs and not others (within the same
sequence of adjacent paragraphs) based on the amount of text in each one
would be disastrous.  Otherwise it's ideal for the units to be as small
as possible as long as they merge such sequences; therefore this uses a
definition corresponding to CSS's idea of elements that establish new
block formatting contexts.

layout/generic/nsBlockFrame.cpp

@@ -6510,6 +6510,12 @@ nsBlockFrame::Init(nsIContent*      aContent,
       aPrevInFlow->GetStateBits() & NS_BLOCK_NEEDS_BIDI_RESOLUTION)
     AddStateBits(NS_BLOCK_NEEDS_BIDI_RESOLUTION);
 
+  if ((GetStateBits() &
+       (NS_FRAME_FONT_INFLATION_CONTAINER | NS_BLOCK_FLOAT_MGR)) ==
+      (NS_FRAME_FONT_INFLATION_CONTAINER | NS_BLOCK_FLOAT_MGR)) {
+    AddStateBits(NS_FRAME_FONT_INFLATION_FLOW_ROOT);
+  }
+
   return rv;
 }