Make RenderObject::style() return a const object

Source/web/tests/WebFrameTest.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 686 matching lines @@
     settings->setViewportEnabled(true);
     settings->setMainFrameResizesAreOrientationChanges(true);
     settings->setShrinksViewportContentToFit(true);
 }
 
 // Helper function to set autosizing multipliers on a document.
 static bool setTextAutosizingMultiplier(Document* document, float multiplier)
 {
     bool multiplierSet = false;
     for (LayoutObject* renderer = document->renderView(); renderer; renderer = renderer->nextInPreOrder()) {
-        if (renderer->style()) {
-            renderer->style()->setTextAutosizingMultiplier(multiplier);
+        if (LayoutStyle* style = renderer->mutableStyle()) {
+            style->setTextAutosizingMultiplier(multiplier);
 
-            EXPECT_EQ(multiplier, renderer->style()->textAutosizingMultiplier());
+            EXPECT_EQ(multiplier, style->textAutosizingMultiplier());
             multiplierSet = true;
         }
     }
     return multiplierSet;
 }
 
 // Helper function to check autosizing multipliers on a document.
 static bool checkTextAutosizingMultiplier(Document* document, float multiplier)
 {
     bool multiplierChecked = false;
@@ skipping 6343 matching lines @@
     EXPECT_EQ(1u, frameClient.navigationalDataReceivedCount());
 
     // Neither should a page reload.
     localFrame->reload();
     EXPECT_EQ(4u, frameClient.provisionalLoadCount());
     EXPECT_FALSE(frameClient.wasLastProvisionalLoadATransition());
     EXPECT_EQ(1u, frameClient.navigationalDataReceivedCount());
 }
 
 } // namespace