Fix typos in <histogram> and <histogram_suffixes> processing

Several typos were landed in https://crrev.com/728635:
* hisotgrams -> histograms
* AddBackMisplacedHisotgrams -> AddBackMisplacedHistograms
* hsitogram_suffixes -> histogram_suffixes

There was also a recursive call to "FixMisplacedHisotgrams" that was
renamed in a previous patchset to AddBackMisplacedHistograms. This has
been updated to "AddBackMisplacedHistograms".

The test has been updated with a comment node inside
"<histogram-configuration>" to exercise this codepath. This has been
manually tested by ensuring
https://chromium-review.googlesource.com/c/chromium/src/+/1988857 can
successfully run "git cl format".

Bug: 1039447
Change-Id: I95097c0d4acd23301a7fad0d9d33521be405aa53
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1988375Reviewed-by: Ilya Sherman <isherman@chromium.org>
Commit-Queue: Philip Rogers <pdr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#728726}

tools/metrics/histograms/pretty_print.py

@@ -101,7 +101,7 @@ def FixMisplacedHistogramsAndHistogramSuffixes(tree):
       tree: The node of the xml tree.
       histograms: A list of histogram nodes inside histogram_suffixes_list
           node. This is a return element.
-      histogram_suffixes: A list of histogram_suffixes nodes inside hisotgrams
+      histogram_suffixes: A list of histogram_suffixes nodes inside histograms
           node. This is a return element.
     """
     for child in tree:
@@ -114,17 +114,17 @@ def FixMisplacedHistogramsAndHistogramSuffixes(tree):
 
   ExtractMisplacedHistograms(tree)
 
-  def AddBackMisplacedHisotgrams(tree):
-    """Adds back those misplaced histogram and hsitogram_suffixes nodes."""
+  def AddBackMisplacedHistograms(tree):
+    """Adds back those misplaced histogram and histogram_suffixes nodes."""
     for child in tree:
       if child.tag == 'histograms':
         child.extend(histograms)
       elif child.tag == 'histogram_suffixes_list':
         child.extend(histogram_suffixes)
       else:
-        FixMisplacedHisotgrams(child)
+        AddBackMisplacedHistograms(child)
 
-  AddBackMisplacedHisotgrams(tree)
+  AddBackMisplacedHistograms(tree)
 
 def PrettyPrintHistograms(raw_xml):
   """Pretty-print the given histograms XML.

tools/metrics/histograms/pretty_print_test.py

@@ -12,6 +12,7 @@ ORIGINAL_XML = """
 <!-- Top level Comment 1 -->
 <!-- Top level Comment 2 -->
 <histogram-configuration>
+<!-- Second level Comment 1 -->
 <histograms>
  <histogram name="Test.Histogram" units="us">
    <owner>person@chromium.org</owner>
@@ -63,6 +64,8 @@ PRETTY_XML = """
 
 <histogram-configuration>
 
+<!-- Second level Comment 1 -->
+
 <histograms>
 
 <histogram name="Foo.Bar" units="xxxxxxxxxxxxxxxxxxyyyyyyyyyyyyyyyyyyyyyyzzzz">