Replace CHECK() with UMA collection of GetLastError().

We have a few clients who are crashing badly when unable to load
ffmpegsumo.dll. Instead of crashing, collect the error code so we
can diagnose without completely breaking these users.

BUG=443019
TBR=isherman

Review URL: https://codereview.chromium.org/808923002

Cr-Commit-Position: refs/heads/master@{#308829}

media/base/media_win.cc

@@ -12,6 +12,7 @@
 #include <delayimp.h>
 
 #include "base/files/file_path.h"
+#include "base/metrics/sparse_histogram.h"
 #include "media/ffmpeg/ffmpeg_common.h"
 
 #pragma comment(lib, "delayimp.lib")
@@ -36,7 +37,10 @@ bool InitializeMediaLibraryInternal(const base::FilePath& module_dir) {
 
   // TODO(scherkus): Remove all the bool-ness from these functions as we no
   // longer support disabling HTML5 media at runtime. http://crbug.com/440892
-  CHECK(initialized);
+  if (!initialized) {
+    UMA_HISTOGRAM_SPARSE_SLOWLY("Media.Initialize.Windows", GetLastError());
+    return false;
+  }
 
   // VS2013 has a bug where FMA3 instructions will be executed on CPUs that
   // support them despite them being disabled at the OS level, causing illegal

tools/metrics/histograms/histograms.xml

@@ -12530,6 +12530,14 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="Media.Initialize.Windows" units="GetLastError">
+  <owner>scherkus@chromium.org</owner>
+  <summary>
+    Errors returned by LoadLibraryEx on Windows while attempting to load
+    ffmpegsumo.dll.
+  </summary>
+</histogram>
+
 <histogram name="Media.InputStreamDuration" units="ms">
   <owner>henrika@chromium.org</owner>
   <summary>