Revert "Raw Clipboard: Add Linux platform specific test."

This reverts commit b6bd9b54.

Reason for revert: This CL is likely causes the build failure for https://ci.chromium.org/p/chromium/builders/ci/Win7%20Tests%20%281%29/100478 and https://ci.chromium.org/p/chromium/builders/ci/Win%207%20Tests%20x64%20%281%29/64768

Original change's description:
> Raw Clipboard: Add Linux platform specific test.
> 
> Bug: 897289
> Change-Id: I26335e58672e915a452dc6ae04dac6d712ccac6b
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2090914
> Auto-Submit: Darwin Huang <huangdarwin@chromium.org>
> Commit-Queue: Victor Costan <pwnall@chromium.org>
> Reviewed-by: Victor Costan <pwnall@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#747546}

TBR=pwnall@chromium.org,huangdarwin@chromium.org

Change-Id: Ie15cb8a2f8e9f41b5c392ca25b557a2e34b1ab10
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 897289
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2091097Reviewed-by: Maggie Cai <mxcai@chromium.org>
Commit-Queue: Maggie Cai <mxcai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#747595}

ui/base/clipboard/clipboard_test_template.h

@@ -733,28 +733,17 @@ TYPED_TEST(ClipboardTest, ReadAvailablePlatformSpecificFormatNamesTest) {
 #endif
 }
 
-// Test that platform-specific functionality works, with a predefined format in
-// On X11 Linux, this test uses a simple MIME type, text/plain.
-// On Windows, this test uses a pre-defined ANSI format, CF_TEXT, and tests that
-// the Windows implicitly converts this to UNICODE as expected.
-#if defined(OS_WIN) || defined(USE_X11)
-TYPED_TEST(ClipboardTest, PlatformSpecificDataTest) {
-  const std::string text = "test string";
+// Test that a platform-specific write works.
 #if defined(OS_WIN)
-  // Windows pre-defined ANSI text format.
+TYPED_TEST(ClipboardTest, WindowsPredefinedFormatWriteDataTest) {
   const std::string kFormatString = "CF_TEXT";
-  // Windows requires an extra '\0' at the end for a raw write.
-  const std::string kPlatformSpecificText = text + '\0';
-#elif defined(USE_X11)
-  const std::string kFormatString = "text/plain";  // X11 text format
-  const std::string kPlatformSpecificText = text;
-#endif
+  const std::string text = "test string";
   base::span<const uint8_t> text_span(
-      reinterpret_cast<const uint8_t*>(kPlatformSpecificText.data()),
-      kPlatformSpecificText.size());
+      reinterpret_cast<const uint8_t*>(text.data()), text.size() + 1);
+
   {
     ScopedClipboardWriter clipboard_writer(ClipboardBuffer::kCopyPaste);
-    clipboard_writer.WriteData(ASCIIToUTF16(kFormatString),
+    clipboard_writer.WriteData(UTF8ToUTF16(kFormatString),
                                mojo_base::BigBuffer(text_span));
   }
 
@@ -763,38 +752,27 @@ TYPED_TEST(ClipboardTest, PlatformSpecificDataTest) {
           ClipboardBuffer::kCopyPaste);
 
   EXPECT_THAT(raw_types, Contains(ASCIIToUTF16(kFormatString)));
-
-#if defined(OS_WIN)
-  // Only Windows ClipboardFormatType recognizes ANSI formats.
   EXPECT_TRUE(this->clipboard().IsFormatAvailable(
       ClipboardFormatType::GetPlainTextAType(), ClipboardBuffer::kCopyPaste));
-#endif  // defined(OS_WIN)
-
-  EXPECT_TRUE(this->clipboard().IsFormatAvailable(
-      ClipboardFormatType::GetPlainTextType(), ClipboardBuffer::kCopyPaste));
 
-  // We're testing platform-specific formats, so use PlatformClipboardTest.
+  // Only ClipboardWin recognizes the Windows-specific CF_TEXT.
   std::string test_suite_name = ::testing::UnitTest::GetInstance()
                                     ->current_test_info()
                                     ->test_suite_name();
   if (test_suite_name == std::string("ClipboardTest/PlatformClipboardTest")) {
     std::string text_result;
     this->clipboard().ReadAsciiText(ClipboardBuffer::kCopyPaste, &text_result);
-    EXPECT_EQ(text_result, text);
-    // Note: Windows will automatically convert CF_TEXT to its UNICODE version.
+    EXPECT_EQ(text, text_result);
+
+    // Windows will automatically convert CF_TEXT to its UNICODE version.
     EXPECT_TRUE(this->clipboard().IsFormatAvailable(
         ClipboardFormatType::GetPlainTextType(), ClipboardBuffer::kCopyPaste));
     base::string16 text_result16;
     this->clipboard().ReadText(ClipboardBuffer::kCopyPaste, &text_result16);
-    EXPECT_EQ(text_result16, base::ASCIIToUTF16(text));
-
-    std::string platform_specific_result;
-    this->clipboard().ReadData(ClipboardFormatType::GetType(kFormatString),
-                               &platform_specific_result);
-    EXPECT_EQ(platform_specific_result, kPlatformSpecificText);
+    EXPECT_EQ(base::ASCIIToUTF16(text), text_result16);
   }
 }
-#endif  // defined(OS_WIN) || defined(USE_X11)
+#endif
 
 #if !defined(OS_MACOSX) && !defined(OS_ANDROID)
 TYPED_TEST(ClipboardTest, HyperlinkTest) {