Workaround for setComposition styling clobber

third_party/WebKit/Source/core/editing/InputMethodControllerTest.cpp

Index: third_party/WebKit/Source/core/editing/InputMethodControllerTest.cpp
diff --git a/third_party/WebKit/Source/core/editing/InputMethodControllerTest.cpp b/third_party/WebKit/Source/core/editing/InputMethodControllerTest.cpp
index cfce7ed4321ce2a651f7a175a04aecf55e470121..8d70b90580a4ccd3d17e69fb6abd415e6dd885a3 100644
--- a/third_party/WebKit/Source/core/editing/InputMethodControllerTest.cpp
+++ b/third_party/WebKit/Source/core/editing/InputMethodControllerTest.cpp
@@ -115,6 +115,30 @@ TEST_F(InputMethodControllerTest, SetCompositionFromExistingText)
     PlainTextRange plainTextRange(PlainTextRange::create(*div, *range));
     EXPECT_EQ(0u, plainTextRange.start());
     EXPECT_EQ(5u, plainTextRange.end());
+
+    controller().setComposition(String("hellobar"), underlines, 8, 8);
+    range = controller().compositionRange();
+    EXPECT_EQ(0, range->startOffset());
+    EXPECT_EQ(8, range->endOffset());
+}
+
+TEST_F(InputMethodControllerTest, SetCompositionKeepingStyle)
+{
+    // (UTF16) 0xac000 0xb098 0xb2e4 0xb77c = "가나다라"

[aelias_OOO_until_Jul13, 2016/09/27 04:55:58]

Can you also add a simpler test case appending and removing single letters to
English text?

[yabinh, 2016/09/27 08:47:20]

Done.

+    Element* div = insertHTMLElement(
+        "<div id='sample' contenteditable='true'><b>&#xac00&#xb098</b>&#xb2e4&#xb77c</div>", "sample");
+
+    Vector<CompositionUnderline> underlines;
+    underlines.append(CompositionUnderline(0, 4, Color(255, 0, 0), false, 0));
+    controller().setCompositionFromExistingText(underlines, 0, 4);
+
+    // (UTF8) 0xEAB080 0xEB8298 0xEB8BA4 0xEB9E8C = "가나다람"
+    controller().setComposition(String::fromUTF8("\xea\xb0\x80\xeb\x82\x98\xeb\x8b\xa4\xeb\x9e\x8c"), underlines, 4, 4);
+    EXPECT_STREQ("<b>가나</b>다람", div->innerHTML().utf8().data());
+
+    // (UTF8) 0xEAB080 0xEB8298 0xEB8BA4 0xeb9dbc = "가나다라"
+    controller().setComposition(String::fromUTF8("\xea\xb0\x80\xeb\x82\x98\xeb\x8b\xa4\xeb\x9d\xbc"), underlines, 4, 4);
+    EXPECT_STREQ("<b>가나</b>다라", div->innerHTML().utf8().data());
 }
 
 TEST_F(InputMethodControllerTest, SelectionOnConfirmExistingText)
@@ -485,7 +509,7 @@ TEST_F(InputMethodControllerTest, CompositionInputEventData)
 
     document().setTitle(emptyString());
     controller().setComposition("ni", underlines, 0, 1);
-    EXPECT_STREQ("beforeinput.data:ni;input.data:ni;", document().title().utf8().data());
+    EXPECT_STREQ("beforeinput.data:i;input.data:i;", document().title().utf8().data());
 
     document().setTitle(emptyString());
     controller().finishComposingText(InputMethodController::KeepSelection);