Do not send redundant selectionchange-events (decouple focus)

third_party/WebKit/Source/web/tests/WebFrameTest.cpp

Index: third_party/WebKit/Source/web/tests/WebFrameTest.cpp
diff --git a/third_party/WebKit/Source/web/tests/WebFrameTest.cpp b/third_party/WebKit/Source/web/tests/WebFrameTest.cpp
index d276af66905c075db75afc84d80e65087912c83b..3abe12672d4824f87d75d9d68a84c94ae2f7fade 100644
--- a/third_party/WebKit/Source/web/tests/WebFrameTest.cpp
+++ b/third_party/WebKit/Source/web/tests/WebFrameTest.cpp
@@ -85,6 +85,7 @@
 #include "modules/mediastream/MediaStreamRegistry.h"
 #include "platform/Cursor.h"
 #include "platform/DragImage.h"
+#include "platform/KeyboardCodes.h"
 #include "platform/PlatformResourceLoader.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/UserGestureIndicator.h"
@@ -109,6 +110,7 @@
 #include "public/platform/WebCachePolicy.h"
 #include "public/platform/WebClipboard.h"
 #include "public/platform/WebFloatRect.h"
+#include "public/platform/WebKeyboardEvent.h"
 #include "public/platform/WebMockClipboard.h"
 #include "public/platform/WebSecurityOrigin.h"
 #include "public/platform/WebThread.h"
@@ -4257,6 +4259,62 @@ TEST_P(ParameterizedWebFrameTest, ClearFocusedNodeTest) {
   EXPECT_EQ(0, webViewHelper.webView()->focusedElement());
 }
 
+class ChangedSelectionCounter : public FrameTestHelpers::TestWebFrameClient {
+ public:
+  ChangedSelectionCounter() : m_callCount(0) {}
+  void didChangeSelection(bool isSelectionEmpty) { ++m_callCount; }
+  int count() const { return m_callCount; }
+  void reset() { m_callCount = 0; }
+
+ private:
+  int m_callCount;
+};
+
+TEST_P(ParameterizedWebFrameTest, TabKeyCursorMoveTriggersOneSelectionChange) {
+  ChangedSelectionCounter counter;
+  FrameTestHelpers::WebViewHelper webViewHelper;
+  registerMockedHttpURLLoad("editable_elements.html");
+  WebViewImpl* webView = webViewHelper.initializeAndLoad(
+      m_baseURL + "editable_elements.html", true, &counter);
+
+  WebKeyboardEvent tabDownEvent(WebInputEvent::KeyDown,
+                                WebInputEvent::NoModifiers,
+                                WebInputEvent::TimeStampForTesting);
+  WebKeyboardEvent tabUpEvent(WebInputEvent::KeyUp, WebInputEvent::NoModifiers,
+                              WebInputEvent::TimeStampForTesting);
+  tabDownEvent.domKey = Platform::current()->domKeyEnumFromString("\t");
+  tabUpEvent.domKey = Platform::current()->domKeyEnumFromString("\t");
+  tabDownEvent.windowsKeyCode = VKEY_TAB;
+  tabUpEvent.windowsKeyCode = VKEY_TAB;
+
+  // Move to the next text-field: 1 cursor change.
+  counter.reset();
+  webView->handleInputEvent(WebCoalescedInputEvent(tabDownEvent));
+  webView->handleInputEvent(WebCoalescedInputEvent(tabUpEvent));
+  EXPECT_EQ(1, counter.count());
+
+  // Move to another text-field: 1 cursor change.
+  webView->handleInputEvent(WebCoalescedInputEvent(tabDownEvent));
+  webView->handleInputEvent(WebCoalescedInputEvent(tabUpEvent));
+  EXPECT_EQ(2, counter.count());
+
+  // Move to a number-field: 1 cursor change.
+  webView->handleInputEvent(WebCoalescedInputEvent(tabDownEvent));
+  webView->handleInputEvent(WebCoalescedInputEvent(tabUpEvent));
+  EXPECT_EQ(3, counter.count());
+
+  // Move to an editable element: 1 cursor change.
+  webView->handleInputEvent(WebCoalescedInputEvent(tabDownEvent));
+  webView->handleInputEvent(WebCoalescedInputEvent(tabUpEvent));
+  EXPECT_EQ(4, counter.count());
+
+  // Move to a non-editable element: 0 cursor changes.
+  // TODO(blink-editing): Once we've fixed crbug.com/692898 test this too:
+  //  webView->handleInputEvent(WebCoalescedInputEvent(tabDownEvent));
+  //  webView->handleInputEvent(WebCoalescedInputEvent(tabUpEvent));
+  //  EXPECT_EQ(4, counter.count());
+}
+
 // Implementation of WebFrameClient that tracks the v8 contexts that are created
 // and destroyed for verification.
 class ContextLifetimeTestWebFrameClient