Rename TestPrerendererClient since that name is already used

In some extreme jumbo configurations the newly added
TestPrerendererClient class in
Source/core/html/parser/HTMLDocumentParserTest.cpp
compiled in the same translation unit as TestPrerendererClient
in Source/core/exported/PrerenderingTest.cpp and then it
didn't compile.

This patch renames TestPre* to MockPre*/MockWebPre* which also matches
a common pattern when creating mock classes.

Change-Id: Ib800e5e65756bf3c3709d8f570982aaa46dc7cd4
Reviewed-on: https://chromium-review.googlesource.com/980332Reviewed-by: Fredrik Söderquist <fs@opera.com>
Reviewed-by: Matthew Cary <mattcary@chromium.org>
Commit-Queue: Daniel Bratell <bratell@opera.com>
Cr-Commit-Position: refs/heads/master@{#545771}

third_party/WebKit/Source/core/html/parser/HTMLDocumentParserTest.cpp

@@ -17,9 +17,9 @@ namespace blink {
 
 namespace {
 
-class TestPrerendererClient : public PrerendererClient {
+class MockPrerendererClient : public PrerendererClient {
  public:
-  TestPrerendererClient(Page& page, bool is_prefetch_only)
+  MockPrerendererClient(Page& page, bool is_prefetch_only)
       : PrerendererClient(page, nullptr), is_prefetch_only_(is_prefetch_only) {}
 
  private:
@@ -29,9 +29,9 @@ class TestPrerendererClient : public PrerendererClient {
   bool is_prefetch_only_;
 };
 
-class TestPrerenderingSupport : public WebPrerenderingSupport {
+class MockWebPrerenderingSupport : public WebPrerenderingSupport {
  public:
-  TestPrerenderingSupport() { Initialize(this); }
+  MockWebPrerenderingSupport() { Initialize(this); }
 
   virtual void Add(const WebPrerender&) {}
   virtual void Cancel(const WebPrerender&) {}
@@ -65,7 +65,7 @@ class HTMLDocumentParserTest : public PageTestBase {
   }
 
  private:
-  TestPrerenderingSupport prerendering_support_;
+  MockWebPrerenderingSupport prerendering_support_;
 };
 
 }  // namespace
@@ -74,7 +74,7 @@ TEST_F(HTMLDocumentParserTest, AppendPrefetch) {
   HTMLDocument& document = ToHTMLDocument(GetDocument());
   ProvidePrerendererClientTo(
       *document.GetPage(),
-      new TestPrerendererClient(*document.GetPage(), true));
+      new MockPrerendererClient(*document.GetPage(), true));
   EXPECT_TRUE(document.IsPrefetchOnly());
   HTMLDocumentParser* parser = CreateParser(document);