Use CAN_USE_CANDIDATE_FORM_FOR_SUGGEST for Firefox.

Strictly speaking, IMM32 spec never requires the application to update
|CANDIDATEFORM| until IMN_OPENCANDIDATE is sent from the IME.

In the case of Mozc, we intentionally do not send IMN_OPENCANDIDATE when
the suggestion window is shown, because doing that can confuse some
applications such as command prompt.

That said, |CANDIDATEFORM::rcArea| is still a useful information that we
want to rely on if it is guaranteed to be kept updated.  For that
purpose, we have maintained a list of applications which are known to
keep |CANDIDATEFORM::rcArea| updated regardless of IMN_OPENCANDIDATE,
and this CL adds "MozillaWindowClass" window class into the whitelist so
that Firefox can be marked with CAN_USE_CANDIDATE_FORM_FOR_SUGGEST
compatibility flag.

BUG=#361
TEST=manually done
REF_BUG=27394949
REF_CL=115815738

Author: yukawa

src/mozc_version_template.txt

@@ -1,6 +1,6 @@
 MAJOR=2
 MINOR=17
-BUILD=2321
+BUILD=2322
 REVISION=102
 # NACL_DICTIONARY_VERSION is the target version of the system dictionary to be
 # downloaded by NaCl Mozc.

src/renderer/win32/win32_renderer_util.cc

@@ -2558,6 +2558,7 @@ int LayoutManager::GetCompatibilityMode(
       const wchar_t *kUseCandidateFormForSuggest[] = {
           L"Chrome_RenderWidgetHostHWND",
           L"JsTaroCtrl",
+          L"MozillaWindowClass",
           L"OperaWindowClass",
           L"QWidget",
       };

src/renderer/win32/win32_renderer_util_test.cc

@@ -4916,7 +4916,7 @@ TEST_F(Win32RendererUtilTest, Firefox_textarea_Suggest) {
   CandidateWindowLayout layout;
   EXPECT_TRUE(layout_mgr.LayoutCandidateWindowForSuggestion(app_info, &layout));
   EXPECT_EXCLUDE_CANDIDATE_WINDOW_LAYOUT(
-      242, 727, 242, 707, 243, 727, layout);
+      242, 727, 242, 707, 242, 727, layout);
 }
 
 // Firefox 3.6.10 on Vista SP1 / textarea
@@ -5396,7 +5396,7 @@ TEST_F(Win32RendererUtilTest, Firefox_ExcludeRect_Suggest) {
   EXPECT_TRUE(layout_mgr.LayoutCandidateWindowForSuggestion(
       app_info, &layout));
   EXPECT_EXCLUDE_CANDIDATE_WINDOW_LAYOUT(
-      86, 142, 86, 122, 87, 142, layout);
+      86, 142, 86, 122, 101, 182, layout);
 }
 
 // Firefox 47.0a1 (2016-02-28)