Introduce RenderingTest::getLayoutObjectByElementId().

third_party/WebKit/Source/core/layout/PaginationTest.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/layout/LayoutBlockFlow.h"
 #include "core/layout/LayoutMultiColumnFlowThread.h"
 
 #include "core/layout/LayoutTestHelper.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace blink {
 
 class PaginationStrutTest : public RenderingTest {
 public:
     int strutForBox(const char* blockId)
     {
-        Node* node = document().getElementById(blockId);
-        if (!node || !node->layoutObject() || !node->layoutObject()->isBox())
+        LayoutObject* layoutObject = getLayoutObjectByElementId(blockId);
+        if (!layoutObject || !layoutObject->isBox())
             return std::numeric_limits<int>::min();
-        LayoutBox* box = toLayoutBox(node->layoutObject());
+        LayoutBox* box = toLayoutBox(layoutObject);
         return box->paginationStrut().toInt();
     }
 
     int strutForLine(const char* containerId, int lineIndex)
     {
-        Node* node = document().getElementById(containerId);
-        if (!node || !node->layoutObject() || !node->layoutObject()->isLayoutBlockFlow())
+        LayoutObject* layoutObject = getLayoutObjectByElementId(containerId);
+        if (!layoutObject || !layoutObject->isLayoutBlockFlow())
             return std::numeric_limits<int>::min();
-        LayoutBlockFlow* block = toLayoutBlockFlow(node->layoutObject());
+        LayoutBlockFlow* block = toLayoutBlockFlow(layoutObject);
         if (block->multiColumnFlowThread())
             block = block->multiColumnFlowThread();
         for (RootInlineBox* line = block->firstRootBox(); line; line = line->nextRootBox(), lineIndex--) {
             if (lineIndex)
                 continue;
             return line->paginationStrut().toInt();
         }
         return std::numeric_limits<int>::min();
     }
 };
@@ skipping 104 matching lines @@
         "    </div>"
         "</div>");
     EXPECT_EQ(0, strutForBox("block1"));
     EXPECT_EQ(0, strutForLine("block1", 0));
     EXPECT_EQ(0, strutForBox("block2"));
     EXPECT_EQ(48, strutForBox("innerBlock"));
     EXPECT_EQ(0, strutForLine("innerBlock", 0));
 }
 
 } // namespace blink