Bug 1626665: part 11) Declare `nsILineIterator::GetNumLines` `const`. r=hsivonen

Depends on D70015

Differential Revision: https://phabricator.services.mozilla.com/D70016

--HG--
extra : moz-landing-system : lando

layout/generic/nsILineIterator.h

@@ -33,7 +33,7 @@ class nsILineIterator {
   /**
    * The number of lines in the block
    */
-  virtual int32_t GetNumLines() = 0;
+  virtual int32_t GetNumLines() const = 0;
 
   /**
    * The prevailing direction of lines.

layout/generic/nsLineBox.cpp

@@ -603,7 +603,7 @@ nsresult nsLineIterator::Init(nsLineList& aLines, bool aRightToLeft) {
   return NS_OK;
 }
 
-int32_t nsLineIterator::GetNumLines() { return mNumLines; }
+int32_t nsLineIterator::GetNumLines() const { return mNumLines; }
 
 bool nsLineIterator::GetDirection() { return mRightToLeft; }
 

layout/generic/nsLineBox.h

@@ -1643,7 +1643,7 @@ class nsLineIterator final : public nsILineIterator {
 
   virtual void DisposeLineIterator() override;
 
-  virtual int32_t GetNumLines() override;
+  virtual int32_t GetNumLines() const override;
   virtual bool GetDirection() override;
   NS_IMETHOD GetLine(int32_t aLineNumber, nsIFrame** aFirstFrameOnLine,
                      int32_t* aNumFramesOnLine,

layout/tables/nsTableRowGroupFrame.cpp

@@ -1693,7 +1693,7 @@ void nsTableRowGroupFrame::SetContinuousBCBorderWidth(LogicalSide aForSide,
 }
 
 // nsILineIterator methods
-int32_t nsTableRowGroupFrame::GetNumLines() { return GetRowCount(); }
+int32_t nsTableRowGroupFrame::GetNumLines() const { return GetRowCount(); }
 
 bool nsTableRowGroupFrame::GetDirection() {
   return (StyleDirection::Rtl ==

layout/tables/nsTableRowGroupFrame.h

@@ -195,7 +195,7 @@ class nsTableRowGroupFrame final : public nsContainerFrame,
   /** Get the number of rows in a row group
    * @return the number of lines in a row group
    */
-  virtual int32_t GetNumLines() override;
+  virtual int32_t GetNumLines() const override;
 
   /** @see nsILineIterator.h GetDirection
    * @return true if the table is rtl