Deprecate 2 PDF Compositor histograms.

Deprecate CompositeDocToPdf.Status and CompositePageToPdf.Status. The
error rates are extremely low. If users are having issues with the PDF
Compositor, the issues will manifest as printing bugs and users will
notice and file bugs for them.

Bug: 975373,975791
Change-Id: I158f1e6edd6cf39525fb606b6805e611f8da5ede
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1699346Reviewed-by: Wei Li <weili@chromium.org>
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#676922}

components/printing/browser/print_composite_client.cc

@@ -8,7 +8,6 @@
 
 #include "base/bind.h"
 #include "base/memory/read_only_shared_memory_region.h"
-#include "base/metrics/histogram_macros.h"
 #include "base/stl_util.h"
 #include "components/printing/common/print_messages.h"
 #include "components/services/pdf_compositor/public/cpp/pdf_service_mojo_types.h"
@@ -206,7 +205,6 @@ void PrintCompositeClient::OnDidCompositePageToPdf(
     mojom::PdfCompositor::CompositePageToPdfCallback callback,
     mojom::PdfCompositor::Status status,
     base::ReadOnlySharedMemoryRegion region) {
-  UMA_HISTOGRAM_ENUMERATION("CompositePageToPdf.Status", status);
   std::move(callback).Run(status, std::move(region));
 }
 
@@ -219,7 +217,6 @@ void PrintCompositeClient::OnDidCompositeDocumentToPdf(
   // Clear all stored printed subframes.
   printed_subframes_.erase(document_cookie);
 
-  UMA_HISTOGRAM_ENUMERATION("CompositeDocToPdf.Status", status);
   std::move(callback).Run(status, std::move(region));
 }
 

tools/metrics/histograms/histograms.xml

@@ -19177,6 +19177,9 @@ uploading your change for review.
 
 <histogram name="CompositeDocToPdf.Status" enum="PdfCompositionStatus"
     expires_after="M77">
+  <obsolete>
+    Removed in July 2019
+  </obsolete>
   <owner>weili@chromium.org</owner>
   <summary>
     Tracks the status of PDF document composition and generation conducted in
@@ -19186,6 +19189,9 @@ uploading your change for review.
 
 <histogram name="CompositePageToPdf.Status" enum="PdfCompositionStatus"
     expires_after="M77">
+  <obsolete>
+    Removed in July 2019
+  </obsolete>
   <owner>weili@chromium.org</owner>
   <summary>
     Tracks the status of PDF page composition and generation conducted in PDF