Switch PdfCompositor UMAs to use kMaxValue enumerator value.

Enums in Mojo have |kMaxValue| automatically defined. Switch
PdfCompositor UMAs to use the 2-parameter UMA_HISTOGRAM_ENUMERATION
macro, which uses |kMaxValue|, and avoid the need for static_casts with
the 3-parameter UMA_HISTOGRAM_ENUMERATION variant.

Along the way, switch the PdfCompositor enum to kFoo style, and fix a
typo to stop referring to composting.

BUG=742517

Change-Id: Id9664371d3b2d7b0fe1203069d96c37b3e4b41de
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1661490Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#669957}

chrome/browser/printing/print_preview_message_handler.cc

@@ -315,7 +315,7 @@ void PrintPreviewMessageHandler::OnCompositePdfPageDone(
     mojom::PdfCompositor::Status status,
     base::ReadOnlySharedMemoryRegion region) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  if (status != mojom::PdfCompositor::Status::SUCCESS) {
+  if (status != mojom::PdfCompositor::Status::kSuccess) {
     DLOG(ERROR) << "Compositing pdf failed with error " << status;
     return;
   }
@@ -386,7 +386,7 @@ void PrintPreviewMessageHandler::OnCompositePdfDocumentDone(
     mojom::PdfCompositor::Status status,
     base::ReadOnlySharedMemoryRegion region) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  if (status != mojom::PdfCompositor::Status::SUCCESS) {
+  if (status != mojom::PdfCompositor::Status::kSuccess) {
     DLOG(ERROR) << "Compositing pdf failed with error " << status;
     return;
   }

chrome/browser/printing/print_view_manager_base.cc

@@ -285,7 +285,7 @@ void PrintViewManagerBase::OnComposePdfDone(
     mojom::PdfCompositor::Status status,
     base::ReadOnlySharedMemoryRegion region) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
-  if (status != mojom::PdfCompositor::Status::SUCCESS) {
+  if (status != mojom::PdfCompositor::Status::kSuccess) {
     DLOG(ERROR) << "Compositing pdf failed with error " << status;
     return;
   }

components/printing/browser/print_composite_client.cc

@@ -206,12 +206,7 @@ void PrintCompositeClient::OnDidCompositePageToPdf(
     mojom::PdfCompositor::CompositePageToPdfCallback callback,
     mojom::PdfCompositor::Status status,
     base::ReadOnlySharedMemoryRegion region) {
-  // Due to https://crbug.com/742517, we can not add and use COUNT for enums in
-  // mojo.
-  UMA_HISTOGRAM_ENUMERATION(
-      "CompositePageToPdf.Status", status,
-      static_cast<int32_t>(mojom::PdfCompositor::Status::COMPOSTING_FAILURE) +
-          1);
+  UMA_HISTOGRAM_ENUMERATION("CompositePageToPdf.Status", status);
   std::move(callback).Run(status, std::move(region));
 }
 
@@ -224,12 +219,7 @@ void PrintCompositeClient::OnDidCompositeDocumentToPdf(
   // Clear all stored printed subframes.
   printed_subframes_.erase(document_cookie);
 
-  // Due to https://crbug.com/742517, we can not add and use COUNT for enums in
-  // mojo.
-  UMA_HISTOGRAM_ENUMERATION(
-      "CompositeDocToPdf.Status", status,
-      static_cast<int32_t>(mojom::PdfCompositor::Status::COMPOSTING_FAILURE) +
-          1);
+  UMA_HISTOGRAM_ENUMERATION("CompositeDocToPdf.Status", status);
   std::move(callback).Run(status, std::move(region));
 }
 

components/services/pdf_compositor/pdf_compositor_impl.cc

@@ -178,7 +178,7 @@ void PdfCompositorImpl::HandleCompositionRequest(
   base::ReadOnlySharedMemoryMapping mapping = serialized_content.Map();
   if (!mapping.IsValid()) {
     DLOG(ERROR) << "HandleCompositionRequest: Cannot map input.";
-    std::move(callback).Run(mojom::PdfCompositor::Status::HANDLE_MAP_ERROR,
+    std::move(callback).Run(mojom::PdfCompositor::Status::kHandleMapError,
                             base::ReadOnlySharedMemoryRegion());
     return;
   }
@@ -208,7 +208,7 @@ mojom::PdfCompositor::Status PdfCompositorImpl::CompositeToPdf(
     base::ReadOnlySharedMemoryRegion* region) {
   if (!shared_mem.IsValid()) {
     DLOG(ERROR) << "CompositeToPdf: Invalid input.";
-    return mojom::PdfCompositor::Status::HANDLE_MAP_ERROR;
+    return mojom::PdfCompositor::Status::kHandleMapError;
   }
 
   DeserializationContext subframes =
@@ -219,14 +219,14 @@ mojom::PdfCompositor::Status PdfCompositorImpl::CompositeToPdf(
   int page_count = SkMultiPictureDocumentReadPageCount(&stream);
   if (!page_count) {
     DLOG(ERROR) << "CompositeToPdf: No page is read.";
-    return mojom::PdfCompositor::Status::CONTENT_FORMAT_ERROR;
+    return mojom::PdfCompositor::Status::kContentFormatError;
   }
 
   std::vector<SkDocumentPage> pages(page_count);
   SkDeserialProcs procs = DeserializationProcs(&subframes);
   if (!SkMultiPictureDocumentRead(&stream, pages.data(), page_count, &procs)) {
     DLOG(ERROR) << "CompositeToPdf: Page reading failed.";
-    return mojom::PdfCompositor::Status::CONTENT_FORMAT_ERROR;
+    return mojom::PdfCompositor::Status::kContentFormatError;
   }
 
   SkDynamicMemoryWStream wstream;
@@ -243,12 +243,12 @@ mojom::PdfCompositor::Status PdfCompositorImpl::CompositeToPdf(
       mojo::CreateReadOnlySharedMemoryRegion(wstream.bytesWritten());
   if (!region_mapping.IsValid()) {
     DLOG(ERROR) << "CompositeToPdf: Cannot create new shared memory region.";
-    return mojom::PdfCompositor::Status::HANDLE_MAP_ERROR;
+    return mojom::PdfCompositor::Status::kHandleMapError;
   }
 
   wstream.copyToAndReset(region_mapping.mapping.memory());
   *region = std::move(region_mapping.region);
-  return mojom::PdfCompositor::Status::SUCCESS;
+  return mojom::PdfCompositor::Status::kSuccess;
 }
 
 void PdfCompositorImpl::CompositeSubframe(FrameInfo* frame_info) {

components/services/pdf_compositor/pdf_compositor_service_unittest.cc

@@ -44,7 +44,7 @@ class PdfCompositorServiceTest : public testing::Test {
 
   void OnCompositeToPdfCallback(mojom::PdfCompositor::Status status,
                                 base::ReadOnlySharedMemoryRegion region) {
-    if (status == mojom::PdfCompositor::Status::SUCCESS)
+    if (status == mojom::PdfCompositor::Status::kSuccess)
       CallbackOnCompositeSuccess(region);
     else
       CallbackOnCompositeStatus(status);
@@ -123,7 +123,7 @@ TEST_F(PdfCompositorServiceTest, InvokeCallbackOnContentError) {
   auto serialized_content = base::ReadOnlySharedMemoryRegion::Create(10);
 
   EXPECT_CALL(*this, CallbackOnCompositeStatus(
-                         mojom::PdfCompositor::Status::CONTENT_FORMAT_ERROR))
+                         mojom::PdfCompositor::Status::kContentFormatError))
       .Times(1);
   compositor_->CompositeDocumentToPdf(
       5u, std::move(serialized_content.region), ContentToFrameMap(),

components/services/pdf_compositor/public/interfaces/pdf_compositor.mojom

@@ -14,10 +14,10 @@ interface PdfCompositor {
   // These values are persisted to logs. Entries should not be renumbered and
   // numeric values should never be reused.
   enum Status {
-    SUCCESS = 0,
-    HANDLE_MAP_ERROR = 1,
-    CONTENT_FORMAT_ERROR = 2,
-    COMPOSTING_FAILURE = 3,
+    kSuccess = 0,
+    kHandleMapError = 1,
+    kContentFormatError = 2,
+    kCompositingFailure = 3,
   };
 
   // Notifies that a subframe is unavailable, such as the render frame process