Allow seeks to zero on streaming sources.

Source/core/html/TimeRangesTest.cpp

 /*
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  *
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  * modification, are permitted provided that the following conditions are
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@@ skipping 280 matching lines @@
     rangesB->add(6, 9);
 
     ASSERT_RANGE("{ [0,2) [4,7) [8,10) }", rangesA);
     ASSERT_RANGE("{ [1,5) [6,9) }", rangesB);
 
     rangesA->intersectWith(rangesB.get());
 
     ASSERT_RANGE("{ [1,2) [4,5) [6,7) [8,9) }", rangesA);
     ASSERT_RANGE("{ [1,5) [6,9) }", rangesB);
 }
+
+TEST(TimeRanges, Nearest)
+{
+    RefPtrWillBeRawPtr<TimeRanges> ranges = TimeRanges::create();
+    ranges->add(0, 2);
+    ranges->add(5, 7);
+
+    ASSERT_EQ(0, ranges->nearest(0));
+    ASSERT_EQ(1, ranges->nearest(1));
+    ASSERT_EQ(2, ranges->nearest(2));
+    ASSERT_EQ(2, ranges->nearest(3));

[philipj_slow, 2014/09/10 12:51:18]

Can you also test the case where the point is exactly in between the ranges? It
may be best to change the ranges to avoid a non-integer 3.5.

The spec says "If two positions both satisfy that constraint (i.e. the new
playback position is exactly in the middle between two ranges in the seekable
attribute) then use the position that is closest to the current playback
position." so you'll have to pass that in as well.

[DaleCurtis, 2014/09/10 17:45:19]

Damn, you caught me! :) I was trying to avoid any more changes here, but in
retrospect it's a tiny change, I'll add it in the separate CL.

+    ASSERT_EQ(5, ranges->nearest(4));
+    ASSERT_EQ(5, ranges->nearest(5));
+    ASSERT_EQ(7, ranges->nearest(8));
+}