Fixes for nonmodal pinch zoom.

cc/layer_tree_host_impl_unittest.cc

Index: cc/layer_tree_host_impl_unittest.cc
diff --git a/cc/layer_tree_host_impl_unittest.cc b/cc/layer_tree_host_impl_unittest.cc
index 278f4676be2d10b3f02d45b483a0165de053de5f..f772155651b711f2fd0cc3e565bb397523fc77c0 100644
--- a/cc/layer_tree_host_impl_unittest.cc
+++ b/cc/layer_tree_host_impl_unittest.cc
@@ -646,7 +646,7 @@ TEST_P(LayerTreeHostImplTest, pinchGesture)
         }
     }
 
-    // Two-finger panning
+    // Two-finger panning should not happen based on pinch events only
     {
         m_hostImpl->setPageScaleFactorAndLimits(1, minPageScale, maxPageScale);
         scrollLayer->setImplTransform(identityScaleTransform);
@@ -661,6 +661,27 @@ TEST_P(LayerTreeHostImplTest, pinchGesture)
 
         scoped_ptr<ScrollAndScaleSet> scrollInfo = m_hostImpl->processScrollDeltas();
         EXPECT_EQ(scrollInfo->pageScaleDelta, pageScaleDelta);
+        EXPECT_TRUE(scrollInfo->scrolls.empty());
+    }
+
+    // Two-finger panning should work with interleaved scroll events
+    {
+        m_hostImpl->setPageScaleFactorAndLimits(1, minPageScale, maxPageScale);
+        scrollLayer->setImplTransform(identityScaleTransform);
+        scrollLayer->setScrollDelta(gfx::Vector2d());
+        scrollLayer->setScrollOffset(gfx::Vector2d(20, 20));
+
+        float pageScaleDelta = 1;
+        m_hostImpl->scrollBegin(gfx::Point(10, 10), InputHandlerClient::Wheel);
+        m_hostImpl->pinchGestureBegin();
+        m_hostImpl->pinchGestureUpdate(pageScaleDelta, gfx::Point(10, 10));
+        m_hostImpl->scrollBy(gfx::Point(10, 10), gfx::Vector2d(-10, -10));
+        m_hostImpl->pinchGestureUpdate(pageScaleDelta, gfx::Point(20, 20));
+        m_hostImpl->pinchGestureEnd();
+        m_hostImpl->scrollEnd();
+
+        scoped_ptr<ScrollAndScaleSet> scrollInfo = m_hostImpl->processScrollDeltas();
+        EXPECT_EQ(scrollInfo->pageScaleDelta, pageScaleDelta);
         expectContains(*scrollInfo, scrollLayer->id(), gfx::Vector2d(-10, -10));
     }
 }